Unsaturated oxime derivatives and the use thereof as latent acids

ABSTRACT

Compounds of formulae I, II or III                                                        
     wherein m is zero or 1; n is 1, 2 or 3; R 1  inter alia is unsubstituted or substituted phenyl, or naphthyl, anthracyl, phenanthryl, a heteroaryl radical, or C 2 -C 12 alkenyl; R′ 1  inter alia is vinylene, phenylene, naphthylene, diphenylene or oxydiphenylene; R 2  inter alia is CN, C 1 -C 4 haloalkyl, C 2 -C 6 alkoxycarbonyl, phenoxycarbonyl, or benzoyl; R 3  inter alia is C 1 -C 18 alkylsulfonyl, phenyl-C 1 -C 3 alkylsulfonyl, camphorylsulfonyl, or phenylsulfonyl; R′ 3  inter alia is C 2 -C 12 alkylenedisulfonyl, phenylenedisulfonyl, naphthylenedisulfonyl, diphenylenedisulfonyl, or oxydiphenylenedisulfonyl; R 4  and R 5  inter alia are hydrogen, halogen, C 1 -C 8 alkyl, C 1 -C 6 alkoxy, C 1 -C 4 haloalkyl, CN, NO 2 , C 2 -C 6 alkanoyl, benzoyl, phenyl, —S-phenyl, OR 6 , SR 9 , NR 7 R 8 , C 2 -C 6 alkoxycarbonyl or phenoxycarbonyl; R 6  inter alia is hydrogen, phenyl or C 1 -C 12 alkyl; R 7  and R 8  inter alia are hydrogen or C 1 -C 12 alkyl; R 9  inter alia is C 1 -C 12  alkyl; R 10 , R 11  and R 12  inter alia are C 1 -C 6 alkyl or phenyl; upon irradiation react as acid generating compounds and thus are suitable in photoresist applications.

The invention relates to new unsaturated oxime derivatives,photopolymerisable compositions comprising said compounds and to the useof the compounds as latent acids, which can be activated by irradiationwith light.

In U.S. Pat. No. 4,540,598 surface-coating compositions based onphotosensitive oxime sulfonates and customary acid-curable resins aredisclosed. In EP 571330 the use ofα-(4-toluene-sulfonyl-oxyimino)-4-methoxybenzyl cyanide andα-(4-toluene-sulfonyloxyimino)-3-thienylmethyl cyanide as latent aciddonors in positive and negative photoresists for wavelengths of 340-390nm, especially those in the radiation region of the mercury i line (365nm) is described. In GB 2306958 the use of oxime-sulfonates as latentacid donors in positive and negative photoresists for wavelengthsbetween 180 and 600 nm, especially those in the radiation region beyond390 nm is reported. In U.S. Pat. No. 5,714,625 non aromaticα-(alkylsulfonyloxyimino)-1-cyclohexenylacetonitriles andα-(alkylsulfonyloxyimino)-1-cyclopentenylacetonitriles are disclosed. InHeterocycles, 38, 71 (1994), G. Nawwar et al. disclose2-(p-tolylsulfonyloxyimino)-3-oxo-5-phenyl-pent-4-enenitrile asexperimental product for investigations on a synthesis forpyrano-pyrroles.

In the art, a need still exists, especially for reactive non-ioniclatent acid donors that are thermally and chemically stable and that,after being activated by light, can be used as catalysts for a varietyof acid-catalysed reactions, such as polycondensation reactions,acid-catalysed depolymerisation reactions, acid-catalysed electrophilicsubstitution reactions or the acid-catalysed removal of protectinggroups. There is also a need for compounds that when irradiated withlight are converted into acids and are capable of acting as solubilityinhibitors in resist formulations. Furthermore there is a need forphotolatent acids which can be bleached upon irradiation.

Surprisingly, it has now been found that specific unsaturated oximederivatives possessing at least one olefinically unsaturated double bondor triple bond which is conjugated with another olefinically unsaturateddouble bond or with an aromatic or heterocyclic double bond, areespecially suitable as catalysts for such reactions. The opticalabsorption spectra of the specific compounds of the invention areparticularly tunable over a wide range of the electromagnetic spectrum.Furthermore they can be bleached upon irradiation.

Accordingly, the present invention pertains to compounds of the formulaeI, II or III

m is zero or 1;

n is 1, 2 or 3;

R₁ is phenyl, which is unsubstituted or substituted by one or more ofthe radicals C₁-C₁₂alkyl, C₁-C₄haloalkyl, halogen, phenyl, OR₆, NR₇R₈,SR₉ and/or —S-phenyl, it being possible for the substituents OR₆, SR₉and NR₇R₈ to form 5- or 6-membered rings, via the radicals R₆, R₇, R₈and/or R₉, with further substituents on the phenyl ring or with one ofthe carbon atoms of the phenyl ring; or R₁ is naphthyl, anthracyl orphenanthryl, wherein the radicals naphthyl, anthracyl and phenanthrylare unsubstituted or substituted by C₁-C₆alkyl, phenyl, OR₆, NR₇R₈, SR₉and/or —S-phenyl, it being possible for the substituents OR₆, SR₉ andNR₇R₈ to form 5- or 6-membered rings, via the radicals R₆, R₇, R₈ and/orR₉ with further substituents on the naphthyl, anthracyl or phenanthrylring or with one of the carbon atoms of the naphthyl, anthracyl orphenanthryl ring; or R₁ is a heteroaryl radical which is unsubstitutedor substituted by C₁-C₆alkyl, phenyl, OR₆, NR₇R₈, SR₉ and/or —S-phenyl,it being possible for the substituents OR₆, SR₉ and NR₇R₈ to form 5- or6-membered rings, via the radicals R₆, R₇, R₈ and/or R₉ with furthersubstituents on the heteroaryl ring or with one of the carbon atoms ofthe heteroaryl ring; or R₁ is C₂-C₁₂alkenyl, C₄-C₈cycloalkenyl, orC₆-C₁₂bicycloalkenyl, with the proviso that the double bond (or thedouble bonds) of the radicals C₂-C₁₂alkenyl, C₄-C₈cycloalkenyl, orC₆-C₁₂bicycloalkenyl is (are) conjugated with the double bondsubstituted by R₄ and R₅; or, if m is zero, R₁ additionally is benzoyl,2-furoyl, 2-thiophenecarbonyl, 2-pyridinecarbonyl or 2-pyrrolecarbonyl,wherein the radicals benzoyl, 2-furoyl, 2-thiophenecarbonyl,2-pyridinecarbonyl or 2-pyrrolecarbonyl are unsubstituted or substitutedby one or more of the radicals C₁-C₁₂alkyl, C₁-C₄haloalkyl, halogen,phenyl, OR₆, NR₇R₈, SR₉ and/or —S-phenyl, it being possible for thesubstituents OR₆, SR₉ and NR₇R₈ to form 5- or 6-membered rings, via theradicals R₆, R₇, R₈ and/or R₉, with further substituents on the benzoyl,2-furoyl, 2-thiophenecarbonyl, 2-pyridinecarbonyl or 2-pyrrolecarbonylring or with one of the carbon atoms of the benzoyl, 2-furoyl,2-thiophenecarbonyl, 2-pyridinecarbonyl or 2-pyrrolecarbonyl ring; or,if m is zero, n is 1 and simultaneously R₅ is phenyl which isunsubstituted or substituted by one or more C₁-C₁₂alkyl, C₁-C₄haloalkyl,halogen, phenyl, OR₆, NR₇R₈, SR₉ and/or —S-phenyl, R₁ additionally ishydrogen or halogen;

R′₁ is vinylene, phenylene, naphthylene,

 diphenylene or oxydiphenylene, wherein the radicals phenylene,naphthylene,

 diphenylene and oxydiphenylene are unsubstituted or substituted byC₁-C₁₂alkyl;

R₂ is CN, C₁-C₄haloalkyl, C₂-C₆alkoxycarbonyl, phenoxycarbonyl,C₁-C₆alkyl-S(O)_(x)—, C₆-C₁₂aryl-S(O)x—, which is unsubstituted orsubstituted by C₁-C₁₂alkyl, or R₂ is C₁-C₆alkyl-SO₂O—, C₆-C₁₀aryl-SO₂O—,diphenyl-phosphinoyl or R₂ is benzoyl which is unsubstituted orsubstituted by CN, NO₂ or C₁-C₄haloalkyl;

x is 1 or 2;

R₃ is C₁-C₁₈alkylsulfonyl, phenyl-C₁-C₃alkylsulfonyl, camphorylsulfonyl,C₁-C₁₀haloalkylsulfonyl, phenylsulfonyl, naphthylsulfonyl,anthracylsulfonyl or phenanthrylsulfonyl, wherein the groups phenyl,naphthyl, anthracyl and phenanthryl of the radicalsphenyl-C₁-C₃alkylsulfonyl, phenylsulfonyl, naphthylsulfonyl,anthracylsulfonyl and phenanthrylsulfonyl are unsubstituted orsubstituted by one or more halogen, C₁-C₄haloalkyl, CN, NO₂,C₁-C₁₆alkyl, phenyl, C₁-C₄alkylthio, OR₆, COOR₉, C₁-C₄alkyl-OCO—,R₉OSO₂— and/or —NR₇R₈; or R₃ is C₂-C₆haloalkanoyl, halobenzoyl,triphenylsilyl, or a group

Y₁, Y₂ and Y₃ are independently of each other O or S;

R′₃ is C₂-C₁₂alkylenedisulfonyl, phenylenedisulfonyl,naphthylenedisulfonyl,

 diphenylenedisulfonyl, or oxydiphenylenedisulfonyl, wherein the groupsphenylene, naphthylene,

 diphenylene and oxydiphenylene of the radicals phenylenedisulfonyl,naphthylenedisulfonyl,

 diphenylenedisulfonyl, or oxydiphenylenedisulfonyl are unsubstituted orsubstituted by C₁-C₁₂alkyl;

R₄ and R₅ are independently of each other hydrogen, halogen, C₁-C₈alkyl,C₁-C₆alkoxy, C₁-C₄haloalkyl, CN, NO₂, C₂-C₆alkanoyl, benzoyl, phenyl,—S-phenyl, OR₆, SR₉, NR₇R₈, C₂-C₆alkoxycarbonyl or phenoxycarbonyl, orR₄ and R₅ together are a direct bond;

R₆ is hydrogen, phenyl, C₁-C₁₂alkyl which is unsubstituted orsubstituted by phenyl, OH, C₁-C₁₂alkoxy, C₁-C₁₂alkylsulfonyl,phenylsulfonyl, (4-methylphenyl)sulfonyl and/or by C₂-C₆alkanoyl, or R₆is C₂-C₁₂alkyl which is interrupted by one or more —O— or —S—, whereinthe interrupted C₂-C₁₂alkyl is unsubtstituted or substituted by phenyl,OH, C₁-C₁₂alkoxy, C₁-C₁₂alkylsulfonyl, phenylsulfonyl,(4-methylphenyl)sulfonyl and/or by C₂-C₆alkanoyl;

R₇ and R₈ are independently of each other hydrogen or C₁-C₁₂alkyl whichis unsubstituted or substituted by OH, C₁-C₄alkoxy, C₁-C₁₂alkylsulfonyl,phenylsulfonyl, (4-methyl-phenyl)sulfonyl and/or C₁-C₆alkanoyl; or R₇and R₈ are C₂-C₁₂alkyl which is interrupted by one or more —O—, whereinthe —O-interrupted C₂-C₁₂alkyl is unsubtstituted or substituted by OH,C₁-C₄alkoxy, C₁-C₁₂alkylsulfonyl, phenylsulfonyl,(4-methylphenyl)sulfonyl and/or C₁-C₆alkanoyl; or R₇ and R₈ are phenyl,C₂-C₆alkanoyl, benzoyl, C₁-C₆alkylsulfonyl, phenylsultonyl,(4-methylphenyl)sulfonyl, naphthylsulfonyl, anthracylsulfonyl orphenanthrylsulfonyl; or R₇ and R₈, together with the nitrogen atom towhich they are bonded, form a 5-, 6- or 7-membered ring which may beinterrupted by —O— or by —NR₆—;

R₉ is C₁-C₁₂ alkyl which is unsubstituted or substituted by OH and/orC₁-C₄alkoxy, or R₉ is C₂-C₁₂alkyl which is interrupted by one or more—O— or —S— and which interrupted C₂-C₁₂alkyl is unsubstituted orsubstituted by OH and/or C₁-C₄alkoxy;

R₁₀, R₁₁ and R₁₂ independently of one another are C₁-C₆alkyl which isunsubstituted or substituted by halogen; or R₁₀, R₁₁ and R₁₂ are phenylwhich is unsubstituted or substituted by C₁-C₄alkyl or halogen; or R₁₁,and R₁₂ together are 1,2-phenylene or C₂-C₆alkylene which isunsubstituted or substituted by C₁-C₄alkyl or halogen;

with the proviso that if m and n both are 1, R₄ and R₅ both are hydrogenand R₁ is phenyl, R₃ is not p-tolylsulfonyl.

C₁-C₁₂alkyl is linear or branched and is, for example, C₁-C₈-, C₁-C₆- orC₁-C₄-alkyl. Examples are methyl, ethyl, propyl, isopropyl, n-butyl,sec-butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl,2,4,4-trimethylpentyl, 2-ethylhexyl, octyl, nonyl, decyl, undecyl,dodecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl,preferably C₁-C₄alkyl, such as methyl, isopropyl or butyl.

C₁-C₈alkyl, C₁-C₆alkyl and C₁-C₄alkyl are likewise linear or branchedand are, for example, as defined above up to the appropriate number ofcarbon atoms. Of interest are, for example, C₁-C₈-, especially C₁-C₆-,preferably C₁-C₄-alkyl, such as methyl or butyl. C₂-C₁₂alkyl, which isinterrupted once or several times by —O—, is interrupted, for example,from one to five times, for example from one to three times or once ortwice, by —O—. Accordingly, resulting structural units are for example:—O(CH₂)₂OH, —O(CH₂)₂OCH₃, —O(CH₂CH₂O)₂CH₂CH₃, —CH₂—O—CH₃,—CH₂CH₂—O—CH₂CH₃, —[CH₂CH₂O]_(y)—CH₃, wherein y=1-5, —(CH₂CH₂O)₅CH₂CH₃,—CH₂—CH(CH₃)—O—CH₂—CH₂CH₃ or —CH₂—CH(CH₃)—O—CH₂—CH₃, —O(CH₂)₂SCH₃,—(CH₂)₂SCH₂CH₃, or —O(CH₂)₂SCH₂CH₃. The interrupting O-atoms and/orS-atoms are non-successive.

C₂-C₁₂alkenyl radicals may be mono or polyunsaturated, linear orbranched and are for example C₂-C₈-, C₂-C₆- or C₂-C₄alkenyl. Examplesare allyl, methallyl, vinyl, 1,1-dimethylallyl, 1-butenyl, 3-butenyl,2-butenyl, 1,3-pentadienyl, 5-hexenyl or 7-octenyl, especially allyl orvinyl.

C₄-C₈cycloalkenyl, may have one or more double bonds and is for exampleC₄-C₆-cycloalkenyl or C₆-C₈-cycloalkenyl. Examples are cyclobutenyl,cyclopentenyl, cyclohexenyl or cyclooctenyl, especially cyclopentenyland cyclohexenyl, preferably cyclohexenyl.

C₆-C₁₂bicycloalkenyl refers to a bicyclic alkenyl group, which maypossess one or more double bonds and wherein the double bonds are eithersituated in the same ring, but may also be situated in both rings. Ifseveral double bonds are present in the bicyclus, the double bonds areconjugated or non-conjugated, preferably the double bonds areconjugated. At least one of the double bonds of the bicycloalkenylradical is conjugated with the double bond of formula I, II, III whichis substituted by the radicals R₄ and R₅. Examples arebicyclo[4.0.4]dodec-3,7-dien-5-yl, bicyclo[4.0.4]dodec-3-en-5-yl,bicyclo[4.0.4]dodec-4-en-6-yl, bicyclo[4.0.3]-non-3-en-5-yl,bicyclo[4.0.3]-non-4-en-6-yl, bicyclo[4.0.3]-non-7-en-8-yl,bicyclo[4.0.3]-non-8-en-7-yl, bicyclo[2.2.1]hept-2-en-3-yl,bicyclo[2.2.2]oct-2-en-3-yl, wherein the examples are referring to thefollowing numbering

C₂-C₁₂alkylene is linear or branched and is, for example, C₂-C₈-, C₂-C₆-or C₂-C₄-alkylene. Examples are ethylene, propylene, butylene,pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecyleneand dodecylene. Preferred is C₁-C₈alkylene, especially C₁-C₆alkylene,preferably C₁-C₄alkylene, such as methylene or butylene.

C₂-C₁₂alkylenedisulfonyl accordingly is an alkylene radical as indicatedabove, which at both “yl”-moieties bears a sulfonyl group. Examples are—SO₂—(CH₂CH₂)_(z)—SO₂—, with z=1-6, e.g. —SO₂—CH₂CH₂—SO₂—, or—SO₂—CH(CH₃)CH₂—SO₂—.

Phenylenedisulfonyl, diphenylenedisulfonyl and oxydiphenylendisulfonylalso bear the sulfonyl groups at the “yl” moiety. Accordingly, resultingstructures are

Substituted phenyl carries from one to five, for example one, two orthree, especially one or two, substituents on the phenyl ring. Thesubstitution is preferably in the 4-, 3,4-, 3,5- or 3,4,5-position ofthe phenyl ring.

When the radicals naphthyl, phenanthryl, heteroaryl and anthracyl aresubstituted by one or more radicals, they are, for example, mono- topenta-substituted, for example mono-, di- or tri-substituted, especiallymono- or di-substituted.

When R₁ is a phenyl radical substituted by OR₆, NR₇R₈ and/or by SR₉ andthe substituents OR₆, NR₇R₈ and SR₉ form 5- or 6-membered rings, via theradicals R₆, R₇, R₈ or R₉, with other substituents on the phenyl ring orwith one of the carbon atoms of the phenyl ring, for example thefollowing structural units are obtained

In the present application, the term “heteroaryl” denotes unsubstitutedand substituted radicals, for example 3-thienyl, 2-thienyl,

wherein R₇ and R₈ are as defined above, thianthrenyl, isobenzofuranyl,xanthenyl, phenoxanthiinyl,

or

wherein X is S, O or NR₇ and R₇ is as defined above. Examples thereofare pyrazolyl, thiazolyl, oxazolyl, isothiazolyl or isoxazolyl. Alsoincluded are, for example, furyl, pyrrolyl, 1,2,4-triazolyl,

or 5-membered ring heterocycles having a fused-on aromatic group, forexample benzimidazolyl, benzothienyl, benzofuranyl, benzoxazolyl andbenzothiazolyl.

Other examples of “heteroaryls” are pyridyl, especially 3-pyridyl,

wherein R₆ is as defined above, pyrimidinyl, pyrazinyl, 1,3,5-triazinyl,2,4-, 2,2- or 2,3-diazinyl, indolizinyl, isoindolyl, indolyl, indazolyl,purinyl, isoquinolyl, quinolyl, phenoxazinyl or phenazinyl. In thisApplication, the term “heteroaryl” also denotes the radicalsthioxanthyl, xanthyl,

wherein R₆, R₇, R₈ and m are as defined above,

or anthraquinonyl. Each of the heteroaryls may carry the substituentsindicated above or in claim 1.

Camphoryl is

Oxydiphenylene is

Diphenyiphosphinoyl is

C₁-C₆alkanoyl is, for example, formyl, acetyl, propionyl, butanoyl orhexanoyl, especially acetyl.

C₁-C₄alkoxy is, for example, methoxy, ethoxy, propoxy and butoxy, itbeing possible for the alkyl radicals in alkoxy groups having more thantwo carbon atoms also to be branched.

C₁-C₄alkylhtio is for example, methylthio, ethylthio, propylthio andbutylthio, it being possible for the alkyl radicals in alkylthio groupshaving more than two carbon atoms also to be branched.

C₂-C₆Alkoxycarbonyl is (C₁-C₅alkyl)-O—C(O)—, wherein C₁-C₅alkyl is asdefined above up to the appropriate number of carbon atoms. Examples aremethoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl orpentyloxycarbonyl, it being possible for the alkyl radicals in alkoxygroups having more than two carbon atoms also to be branched.

C₁-C₁₀Haloalkyl and C₁-C₄haloalkyl are C₁-C₁₀- and C₁-C₄-alkyl mono- orpoly-substituted by halogen, C₁-C₁₀- and C₁-C₄-alkyl being, for example,as defined above. There are, for example, from one to three or one ortwo halogen substituents at the alkyl radical. Examples arechloromethyl, trichloromethyl, trifluoromethyl or 2-bromopropyl,especially trifluoromethyl or trichloromethyl.

C₂-C₆haloalkanoyl is (C₁-C₅haloalkyl)-C(O)—, wherein C₁-C₅haloalkyl isas defined above up to the appropriate number of carbon atoms. Examplesare chloroacetyl, trichloroacetyl, trifluoroacetyl,pentafluoropropionyl, perfluorooctanoyl, or 2-bromopropionyl, especiallytrifluoroacetyl or trichloroacetyl.

Halobenzoyl is benzoyl which is mono- or poly-substituted by halogenand/or C₁-C₄haloalkyl, C₁-C₄-haloalkyl being as defined above. Examplesare pentafluorobenzoyl, trichlorobenzoyl, trifluoromethylbenzoyl,especially pentafluorobenzoyl.

Halogen is fluorine, chlorine, bromine or iodine, especially chlorine orfluorine, preferably fluorine

In a group C₆-C₁₀arylS(O)_(x)— which is unsubstituted or substituted byC₁-C₁₂alkyl, the aryl radical is for example phenyl, tolyl,dodecylphenyl or 1- or 2-naphthyl.

Phenyl-C₁-C₃alkyl is, for example, benzyl, 2-phenylethyl,3-phenylpropyl, α-methylbenzyl or α,α-dimethylbenzyl, especially benzyl.

When R₇ and R₈ together with the nitrogen atom to which they are bondedform a 5-, 6- or 7-membered ring that may be interrupted by —O— or by—NR₆—, for example the following structures are obtained

The definitions C₁-C₁₈alkylsulfonyl, phenyl-C₁-C₃alkylsulfonyl,camphorylsulfonyl, C₁-C₁₀haloalkylsulfonyl refer to the correspondingradicals C₁-C₁₈alkyl, phenyl-C₁-C₃alkyl, camphoryl and C₁-C₁₀haloalkyl,as described in detail above, being linked to a sulfonyl group (—SO₂—).Accordingly, also phenylsulfonyl, naphthylsulfonyl, anthracylsulfonyland phenanthrylsulfonyl refer to the corresponding radicals linked to asulfonyl group.

The terms “and/or” or “or/and” in the claims are meant to express thatnot only one of the defined alternatives (substituents) may be present,but also several of the defined alternatives (substituents) together,namely mixtures of different alternatives (substituents).

The term “at least” is meant to define one or more than one, for exampleone or two or three, preferably one or two.

Preference is given to compounds of formula I and II, wherein

m is zero or 1;

n is 1;

R₁ is unsubstituted phenyl or phenyl which is substituted by C₁-C₆alkyl,phenyl, OR₆, SR₉, —S-phenyl, halogen and/or by NR₇R₆, it being possiblefor the substituents OR₆, and NR₇R₈ to form 5- or 6-membered rings, viathe radicals R₆, R₇ and/or R₈ with further substituents of the phenylring, or with one of the carbon atoms of the phenyl ring; or R₁ isC₄-C₈cycloalkenyl or C₆-C₁₂bicycloalkenyl;

R′₁ is phenylene, naphthylene,

 diphenylene or oxydiphenylene, wherein the radicals phenylene,naphthylene,

 diphenylene and oxydiphenylene are unsubstituted or substituted byC₁-C₁₂alkyl.

Specifically preferred are compounds of formula I, wherein n is 1, m iszero or 1, R₁ is unsubstituted phenyl or phenyl substituted byC₁-C₄alkyl or OR₆; R₂ is CN; R₃ is C₁-C₄alkylsulfonyl; and R₄ and R₅independently of each other are hydrogen or C₁-C₄alkyl.

Other interesting compounds are those of formula I, wherein n is 1; m is0; R₁ is unsubstituted phenyl or phenyl substituted once or twice byC₁-C₄alkyl, C₁-C₄alkoxy or halogen; R₂ is CN or trifluoromethyl; R₃ isC₁-C₁₆alkylsulfonyl or unsubstituted or C₁-C₄alkyl-substitutedphenylsulfonyl; R₄ and R₅ independently of each other are hydrogen,C₁-C₄alkyl, phenyl, C₁-C₄alkoxy or C₂-C₆alkoxycarbonyl.

Compounds of the formula I, wherein m is 0 and n is 1 are specificallypreferred and in the following are referred to as compounds of theformula Ia

wherein

R₁, R₂, R₃, R₄ and R₅ are as defined above.

Preferred are compounds of formula Ia, wherein

R₁ is unsubstituted phenyl or phenyl substituted once or twice byC₁-C₄alkyl, OR₆ or halogen or R₁ is cyclohexenyl, furyl or thienyl;

R₂ is CN or trifluoromethyl;

R₃ is C₁-C₁₆alkylsulfonyl; camphorylsulfonyl; or phenylsulfonyl which isunsubstituted or substituted 1-5 times by C₁-C₁₂alkyl, C₁-C₄alkoxy,C₁-C₄haloalkyl, C₁-C₄alkylthio, NO₂ or halogen; or R₃ is—P(O)(OR₁₁)(OR₁₂);

R₄ and R₅ independently of each other are hydrogen, C₁-C₄alkyl, phenyl,C₁-C₄alkoxy or C₂-C₆alkoxycarbonyl;

R₆ is C₁-C₄alkyl or C₁-C₄alkylsulfonyl; and

R₁₁, R₁₂ are C₁-C₆alkyl or phenyl.

Further compounds of interest are those wherein in the formula Ia,

R₁ is a heteroaryl radical that is unsubstituted or mono- orpoly-substituted by C₁-C₆alkyl, phenyl, OR₆, SR₉, —S-phenyl and/or byNR₇R₈, it being possible for the substituents OR₆ and NR₇R₈ to form 5-or 6-membered rings, via the radicals R₆, R₇ and/or R₈, with furthersubstituents or with one of the carbon atoms of the heteroaryl ring, orR₁ is benzoyl, 2-furoyl, 2-thiophenecarbonyl, 2-pyridinecarbonyl or2-pyrrolecarbonyl, the radicals benzoyl, 2-furoyl, 2-thiophenecarbonyl,2-pyridinecarbonyl or 2-pyrrolecarbonyl being unsubstituted orsubstituted by one or more of the radicals C₁-C₁₂alkyl, C₁-C₄haloalkyl,halogen, phenyl, OR₆, NR₇R₈, SR₉ and/or —S-phenyl.

Further compounds of interest are those of the formula II, wherein R′₁is phenylene, naphthylene,

diphenylene or oxydiphenylene, the radicals phenylene, naphthylene,

diphenylene and oxydiphenylene being unsubstituted or substituted byC₁-C₁₂alkyl;

Mention should be made of compounds of formula Ia and II wherein R₂ isCN, C₂-C₆alkoxycarbonyl, C₁-C₄haloalkyl, C₁-C₆alkylS(O)_(x)—,unsubstituted C₆-C₁₀arylS(O)_(x)— or C₆-C₁₀arylS(O)_(x)— which issubstituted by C₁-C₁₂alkyl.

Most preferred compounds are those of formula Ia, where R₁ is phenyl(optionally substituted as defined above) or a heteroaryl radical(optionally substituted as defined above) and R₂ is CN.

Preference is given especially to compounds of formula Ia and II wherein

R₆ is C₁-C₆alkyl which is unsubstituted or substituted by OH,C₁-C₄alkoxy, C₁-C₁₂alkylsulfonyl, phenylsulfonyl,(4-methylphenyl)sulfonyl and/or by C₂-C₆alkanoyl or R₆ is C₂-C₆alkylwhich is interrupted by —O—, wherein the interrupted C₂-C₆alkyl radicalis unsubstituted or substituted by OH, C₁-C₄alkoxy, C₁-C₁₂alkylsulfonyl,phenylsulfonyl, (4-methylphenyl)sulfonyl and/or by C₂-C₆alkanoyl.

Preference is given also to compounds of formula Ia and II wherein

R₃ is C₁-C₁₈alkylsulfonyl, C₁-C₁₀haloalkylsulfonyl, or phenylsulfonylwhich is unsubstituted or substituted by halogen, NO₂, C₁-C₄haloalkyl,C₁-C₁₆alkyl or C₁-C₁₂alkyl, OR₆, COOR₉ and/or by —OCO—C₁-C₄alkyl.

Preference is given likewise compounds of formula Ia and II wherein

R₄ and R₅ are independently of each other hydrogen, halogen, C₁-C₆alkyl,phenyl, C₁-C₆alkoxy or C₂-C₆alkoxycarbonyl;

R₇ and R₈ are independently of each other hydrogen or C₁-C₁₂alkyl whichis unsubstituted or substituted by OH, C₁-C₄alkoxy, C₁-C₁₂alkylsulfonyl,phenylsulfonyl, (4-methylphenyl)sulfonyl and/or by C₁-C₆alkanoyl; or areC₂-C₁₂alkyl which is interrupted by —O—, wherein the interruptedC₂-C₁₂alkyl is unsubstituted or substituted by OH, C₁-C₄alkoxy,C₁-C₁₂alkylsulfonyl, phenylsulfonyl, (4-methylphenyl)sulfonyl and/or byC₁-C₆alkanoyl; or R₇ and R₈ are phenyl, C₂-C₆alkanoyl, benzoyl,C₁-C₆alkylsulfonyl, phenylsulfonyl, (4-methylphenyl)sulfonyl,naphthylsulfonyl, anthracylsulfonyl or phenanthrylsulfonyl; or R₇ andR₈, together with the nitrogen atom to which they are bonded, form a 5-,6- or 7-membered ring which may be interrupted by —O— or by —NR₆—; and

R₉ is C₁-C₁₂alkyl which is unsubstituted or substituted by OH and/or byC₁-C₄alkoxy or is C₂-C₁₂alkyl which is interrupted by —O—, wherein theinterrupted C₂-C₁₂alkyl is unsubstituted or substituted by OH and/orC₁-C₄alkoxy.

Specific examples of compounds according to the present invention are

2-Methylsulfonyloxyimino-4-phenyl-but-3-enenitrile;

2-Methylsulfonyloxyimino-4-p-tolyl-but-3-enenitrile;

2-Methylsulfonyloxyimino-4-(4-methoxy-phenyl)-but-3-enenitrile;

2-Methylsulfonyloxyimino-3-methyl-4-phenyl-but-3-enenitrile;

2-Methylsulfonyloxyimino-3-oxo-5-phenyl-pent-4-enenitrile;

4-Cyano-4-(p-tolylsulfonyloxyimino)-2-phenyl-but-2-enoic acid ethylester;

4-Cyclohex-1-enyl-2-methylsulfonyloxyimino-but-3-enenitrile;

1,1,1-Trifluoro-4-(4-methylsulfanyl-phenyl)-but-3-en-2-oneO-(10-camphorsulfonyl)-oxime;

1,1,1-Trifluoro-4-(4-methoxy-phenyl)-but-3-en-2-oneO-(p-tolylsulfonyl)-oxime;

2-(4-Chloro-benzylidene)-3-methylsulfonyloxyimino-succinonitrile;

2-Octylsulfonyloxyimino-4-(2-methoxy-phenyl)-but-3-enenitrile;

2-Benzoyl-4-methylsulfonyloxyimino-3-phenyl-pent-2-enedinitrile;

2-Dodecylsulfonyloxyimino-4-thiophen-2-yl-but-3-enenitrile;

4-Furan-2-yl-2-isopropylsulfonyloxyimino-but-3-enenitrile;

3-Hexyl-2-diphenylphosphoryloxyimino-4-phenyl-but-3-enenitrile;

4-{4-[4-(3-Cyano-3-butylsultonyloxyimino-propenyl)-benzenesultonyl]-phenyl}-2-butylsulfonyloxyimino-but-3-enenitrile;

4-[4′-(3-Cyano-3-(p-tolylsulfonyloxyimino)-propenyl)-biphenyl-4-yl]-2-(p-tolylsulfonyloxyimino)-but-3-enenitrile;

4-{4-[4-(3-Cyano-3-methylsulfonyloxyimino-propenyl)-phenoxy]-phenyl}-2-methylsulfonyloxyimino-but-3-enenitrile;

2-Pentafluorophenylsulfonyloxyimino-4-phenyl-but-3-ynenitrile;

2-Ethylsulfonyloxyimino-3-(3-methoxy-phenyl)-but-3-enenitrile;

4-{4-[4-(3-Cyano-3-methanesulfonyloxyimino-propenyl)-benzyl]-phenyl}-2-methanesultonyloxyimino-but-3-enenitrile;

2-[4′-(1-Cyano-3-p-toly-allylideneaminooxysulfonyl)-biphenyl-4-ylsulfonyloxyimino]-4-p-tolyl-but-3-enenitrile.

The invention also relates to mixtures of isomeric forms of thecompounds of formula I, Ia, II and III. The double bond of the oximinogroup can exist in both the syn (cis, Z) and the anti (trans, E) form oras mixtures of the two geometrical isomers. In addition, the n doublebonds of formulae I, II and III can, depending on the substituents R₄and R₅, exhibit two (Z and E)) configurations. In the present invention,both the individual geometrical isomers and any mixtures of two or moregeometrical isomers can be used.

Unsaturated oxime esters (of formulae I, Ia, II and III) can be preparedby methods described in the literature, for example by reacting suitablefree oximes (R₃ and R′₃=H) with the desired (for example, sulfonic) acidhalides (for example, R₃Cl or Cl—R′₃—Cl).

R₁, R₂, R₃, R₃′, R₄, R₅, n and m are defined as described above.

These reactions are carried out in an inert solvent such as toluene,tetrahydrofuran (THF) or dimethylformamide (DMF) in the presence of abase, for example a tertiary amine, such as triethylamine, or byreaction of the salt of an oxime with the desired acid chloride. Thesemethods are disclosed, for example, in EP 48615. The sodium salts ofoximes can be obtained, for example, by reacting the oxime in questionwith a sodium alcoholate in dimethylformamide.

The starting unsaturated oximes (R₃=H) can be prepared in numerous ways,which are known to the person skilled in the art, for example by thenitrosation of “active” methylene groups with nitrous acid or an alkylnitrite. Both alkaline conditions, as described for example in OrganicSyntheses coll. Vol. VI (J. Wiley & Sons, New York, 1988), pp 199 and840, and acidic conditions, as described, for example, in OrganicSynthesis col. Vol V, pp 32 and 373, coll. Vol. III, pp 191 and 513,coll. Vol.II, pp. 202, 204 and 363, are suitable for the preparation ofthe oximes used as starting materials in the invention. Nitrous acid isusually generated from sodium nitrite. The alkyl nitrite can be forexample methyl nitrite, ethyl nitrite, isopropyl nitrite, butyl nitrite,isoamyl nitrite. Another example is the oximation of cinnamaldehydes(Synthesis 1994, 573) followed by cyanation (J. Org. Chem. 1993, 58,2075). The most useful intermediates for the preparation of theunsaturated oximes of the invention are for example cinnamaldehydederivatives and 4-aryl-but-3-ene nitriles. These intermediates areobtained by various methods depending on the particular structuredesired. Examples of useful synthetic methods applicable to thesynthesis of the intermediates are the condensation of aromaticaldehydes with acetaldehyde (Arch. Pharm. 1996, 329, 125), thecyanohydrin ester formation followed by reduction (Synthesis 1996, 1188;J. Org. Chem. 1983, 48, 3545), the Wittig/Horner reactions (Chem. Pharm.Bull. 1985, 33, 3558; Bull. Soc. Chim. Fr. 1974, 2065; J. Chem. Soc.Perkin Trans. 2, 1992, 1207), and the Heck reaction (R. F. Heck,Palladium Reagents in Organic Syntheses, Academic Press, London, 1985;J. Chem. Soc. 1993, 1943).

Oximes can also be obtained by reacting a suitable carbonyl orthionylcarbonyl compound with hydroxylamine or a hydroxylammonium salt.

The invention relates also to the use of compounds of formulae I, II andIII as described above, as photoinitiators for compounds that can becrosslinked under the action of an acid and/or as solubility inhibitorsfor compounds the solubility of which is altered under the action of anacid, as well as to a method of crosslinking compounds which can becrosslinked under the action of an acid, which method comprises adding acompound of formula I, II and/or III as described above to theabove-mentioned compounds and irradiating imagewise or over the wholearea with light having a wavelength in the range of 180-1500 nm.

In photocrosslinkable compositions, the unsaturated oxime derivatives ofthe invention act as latent curing catalysts: when irradiated with lightthey release acid which catalyses the crosslinking reaction. Inaddition, the acid released by the radiation can, for example, catalysethe removal of suitable acid-sensitive protecting groups from a polymerstructure, or the cleavage of polymers containing acid-sensitive groupsin the polymer backbone. Other applications are, for example,colour-change systems based on a change in the pH or in the solubilityof, for example, a pigment protected by acid-sensitive protectinggroups.

Compositions using pH sensitive dyes or latent pigments in combinationwith oxime derivatives according to the invention can be used asindicators for electromagnetic radiation, such as gamma radiation,electron beams, UV- or visible light, or simple throw away dosimeters.Especially for light, that is invisible to the human eye, like UV- orIR-light, such dosimeters are of interest.

Finally, oxime derivatives which are sparingly soluble in anaqueous-alkaline developer can be rendered soluble in the developer bymeans of light-induced conversion into the free acid, with the resultthat they can be used as solubility inhibitors in combination withsuitable film-forming resins.

The invention therfore also pertains to a composition comprising

a) at least one compound that can be crosslinked under the action of anacid and/or

b) at least one compound the solubility of which is altered under theaction of an acid and

c) as latent acid photoinitiator, at least one compound of the formulaeI, II or III as described above.

These compositions may in addition to component c) comprise furtherphotoinitiators, sensitizers and/or additives.

Resins which can be crosslinked by acid catalysis are, for example,mixtures of polyfunctional alcohols or hydroxy-group-containing acrylicand polyester resins, or partially hydrolysed polyvinylacetals orpolyvinyl alcohols with polyfunctional acetal derivatives. Under certainconditions, for example the acid-catalysed self-condensation ofacetal-functionalised resins is also possible.

In addition, oximesulfonates of formula I, II and III can be used, forexample, as hardeners, which can be activated by light, for siloxanegroup-containing resins. These resins can, for example, either undergoself-condensation by means of acid-catalysed hydrolysis or becrosslinked with a second component of the resin, such as apolyfunctional alcohol, a hydroxy-group-containing acrylic or polyesterresin, a partially hydrolysed polyvinyl acetal or a polyvinyl alcohol.That type of polycondensation of polysiloxanes is described, forexample, in J. J. Lebrun, H. Pode, Comprehensive Polymer Science, Vol.5, p. 593, Pergamon Press, Oxford, 1989.

It is desirable in these reactions for the acid to be released whenirradiated with light of various wavelengths. Surprisingly, it has beenfound that the new unsaturated oxime derivatives according to theinvention are thermally and chemically stable, exhibit very high lightsensitivity, and are capable of releasing the acid when irradiated withlight. In addition the compounds are rapidly bleached after exposure tolight, a property which is very helpful for homogeneous generation ofthe acid throughout the entire thickness of the compositions irradiatedwith the light. This property is used for the curing of thick layers orthe production of colourless articles with visible light.

The new unsaturated oxime derivatives of formula I, II and III, asalready mentioned above can be used as hardeners, which can be activatedby light, for acid-curable resins. Suitable acid-curable resins are allresins the curing of which can be accelerated by acid catalysts, such asaminoplasts or phenolic resole resins. These resins are especiallymelamine, urea, epoxy, phenolic, acrylic, polyester and alkyd resins,but especially mixtures of acrylic, polyester or alkyd resins with amelamine resin. Also included are modified surface-coating resins, suchas acrylic-modified polyester and alkyd resins. Examples of individualtypes of resins that are covered by the expression acrylic, polyesterand alkyd resins are described, for example, in Wagner,Sarx/Lackkunstharze (Munich, 1971), pages 86 to 123 and 229 to 238, orin Ullmann/Encyclopädie der techn. Chemie, 4th Edition, Volume 15(1978), pages 613 to 628, or Ullmann's Encyclopedia of IndustrialChemistry, Verlag Chemie, 1991, Vol. 18, 360 ff., Vol. A19, 371 ff.

The composition can for example be used as a surface coating. Thesurface coating preferably comprises an amino resin. Examples thereofare etherified or non-etherified melamine, urea, guanidine or biuretresins. Acid catalysis is especially important in the curing of surfacecoatings comprising etherified amino resins, such as methylated orbutylated melamine resins (N-methoxymethyl- or N-butoxymethyl-melamine)or methylated/butylated glycolurils. Examples of other resincompositions are mixtures of polyfunctional alcohols orhydroxy-group-containing acrylic and polyester resins, or partiallyhydrolysed polyvinyl acetate or polyvinyl alcohol with polyfunctionaldihydropropanyl derivatives, such as derivatives of3,4-dihydro-2H-pyran-2-carboxylic acid. As already mentioned above, forexample polysiloxanes can also be crosslinked using acid catalysis.Other cationically polymerisable materials that are suitable for thepreparation of surface coatings are ethylenically unsaturated compoundspolymerisable by a cationic mechanism, such as vinyl ethers, for examplemethyl vinyl ether, isobutyl vinyl ether, trimethylolpropane trivinylether, ethylene glycol divinyl ether; cyclic vinyl ethers, for example3,4-dihydro-2-formyl-2H-pyran (dimeric acrolein) or the3,4-dihydro-2H-pyran-2-carboxylic acid ester of2-hydroxymethyl-3,4-dihydro-2H-pyran; vinyl esters, such as vinylacetate and vinyl stearate, mono- and di-olefins, such asα-methylstyrene, N-vinylpyrrolidone or N-vinylcarbazole.

For certain purposes, resin mixtures having monomeric or oligomericconstituents containing polymerisable unsaturated groups are used. Suchsurface coatings can also be cured using compounds of formula I, II orIII. In that process, a) radical polymerisation initiators or b)photoinitiators can additionally be used. The former initiatepolymerisation of the unsaturated groups during heat treatment, thelatter during UV irradiation.

According to the invention, the compositions, which can be activated bylight, may comprise further photoinitiators, sensitisers and/oradditives in addition to component c), or the compounds of formula I, IIor III can be used together with further photoinitiators, sensitisersand/or additives.

Examples of additional photoinitiators are radical photoinitiators, suchas those from the class of the benzophenones, acetophenone derivatives,such as α-hydroxycycloalkylphenyl ketone, dialkoxyacetophenone,α-hydroxy-acetophenone or α-amino-acetophenone, 4-aroyl-1,3-dioxolans,benzoin alkyl ethers and benzil ketals, monoacylphosphine oxides,bisacylphosphine oxides or titanocenes, camphor quinone, phenylglyoxalicesters and derivatives thereof, dimeric phenylglyoxalic esters,peresters, e.g. benzophenone tetracarboxylic peresters as described forexample in EP 126541, ferrocenium compounds, or titanocenes, e.g.bis(cyclopentadienyl)-bis(2,6-difluoro-3-pyrryl-phenyl)titanium.

Examples of especially suitable additional photoinitiators are:1-(4-dodecylbenzoyl)-1-hydroxy-1-methyl-ethane,1-(4-isopropylbenzoyl)-1-hydroxy-1-methyl-ethane,1-benzoyl-1-hydroxy-1-methyl-ethane,1-[4-(2-hydroxyethoxy)-benzoyl]-1-hydroxy-1-methyl-ethane,1-[4-(acryloyloxyethoxy)-benzoyl]-1-hydroxy-1-methyl-ethane, diphenylketone, phenyl-1-hydroxycyclohexyl ketone,(4-morpholinobenzoyl)-1-benzyl-1-dimethylamino-propane,1-(3,4-dimethoxyphenyl)-2-benzyl-2-dimethylamino-butan-1-one,(4-methylthiobenzoyl)-1-methyl-1-morpholino-ethane, benzil dimethylketal, bis(cyclopentadienyl)-bis(2,6-difluoro-3-pyrryl-phenyl)titanium,trimethylbenzoyldiphenylphosphine oxide,bis(2,6-dimethoxy-benzoyl)-(2,4,4-trimethyl-pentyl)-phosphine oxide,bis(2,4,6-trimethylbenzoyl)-2,4-dipentyloxyphenyl-phosphine oxide orbis(2,4,6-trimethylbenzoyl)phenyl-phosphine oxide. Further suitableadditional photoinitiators are to be found in U.S. Pat. No. 4,950,581,column 20, line 35 to column 21, line 35. Other examples aretrihalomethyltriazine derivatives or hexaarylbisimidazolyl compounds,e.g.2-[2-(4-methoxy-phenyl)-vinyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-(4-methoxy-phenyl)-4,6-bis-trichloromethyl-[1,3,5]triazine,2-(3,4-dimethoxy-phenyl)-4,6-bis-trichloromethyl-[1,3,5]-triazine,2-methyl-4,6-bis-trichloromethyl-[1,3,5]triazine,hexaarylbisimidazole/coinitiators systems, e.g.ortho-chlorohexaphenyl-bisimidazole combined with2-mercaptobenzthiazole. Further examples for additional photoinitiatorsare borate compounds, as for example described in U.S. Pat. No.4,772,530, EP 775706, GB 2307474, GB 2307473 and GB 2304472. The boratecompounds preferably are used in combination with electron acceptorcompounds, such as, for example dye cations, or thioxanthonederivatives.

Further examples of additional photoinitiators are, for example,peroxide compounds, e.g. benzoyl peroxide (other suitable peroxides aredescribed in U.S. Pat. No. 4,950,581, column 19, lines 17-25) orcationic photoinitiators, such as aromatic sulfonium or iodonium salts,such as those to be found in U.S. Pat. No. 4,950,581, column 18, line 60to column 19, line 10, or cyclopentadienyl-arene-iron(II) complex salts,for example (η⁶-isopropylbenzene)(η⁵-cyclopentadienyl)-iron(II)hexafluorophosphate.

The surface coatings may be solutions or dispersions of thesurface-coating resin in an organic solvent or in water, but they mayalso be solventless. Of special interest are surface coatings having alow solvent content, so-called “high solids surface coatings”, andpowder coating compositions. The surface coatings may be clear lacquers,as used, for example, in the automobile industry as finishing lacquersfor multilayer coatings. They may also comprise pigments and/or fillers,which may be inorganic or organic compounds, and metal powders for metaleffect finishes.

The surface coatings may also comprise relatively small amounts ofspecial additives customary in surface-coating technology, for exampleflow improvers, thixotropic agents, leveling agents, antifoaming agents,wetting agents, adhesion promoters, light stabilisers, antioxidants, orsensitisers. UV absorbers, such as those of thehydroxyphenyl-benzotriazole, hydroxyphenyl-benzophenone, oxalic acidamide or hydroxyphenyl-s-triazine type may be added to the compositionsaccording to the invention as light stabilisers. Individual compounds ormixtures of those compounds can be used with or without the addition ofsterically hindered amines (HALS).

Examples of such UV absorbers and light stabilisers are

1. 2-(2′-Hydroxvyhenyl)-benzotriazoles, such as2-(2′-hydroxy-5′-methylphenyl)-benzotriazole,2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)-benzotriazole,2-(5′-tert-butyl-2′-hydroxyphenyl)-benzotriazole,2-(2′-hydroxy-5′-(1,1,3,3-tetramethylbutyl)phenyl)-benzotriazole,2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)-5-chloro-benzotriazole,2-(3′-tert-butyl-2′-hydroxy-5′-methylphenyl)-5-chloro-benzotriazote,2-(3′-sec-butyl-5′-tert-butyl-2′-hydroxyphenyl)-benzotriazole,2-(2′-hydroxy-4′-octyloxyphenyl)-benzotriazole,2-(3′,5′-di-tert-amyl-2′-hydroxyphenyl)-benzotriazole,2-(3′,5′-bis-(α,α-dimethylbenzyl)-2′-hydroxyphenyl)-benzotriazole,mixture of2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)-5-chloro-benzotriazole,2-(3′-tert-butyl-5′-[2-(2-ethyl-hexyloxy)-carbonylethyl]-2′-hydroxyphenyl)-5-chloro-benzotriazole,2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl)-5-chloro-benzotriazole,2(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl)-benzotriazole,2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)-benzotriazole,2-(3′-tert-butyl-5′-[2-(2-ethylhexyloxy)carbonylethyl]-2′-hydroxyphenyl)-benzotriazole,2-(3′-dodecyl-2′-hydroxy-5′-methylphenyl)-benzotriazole and2-(3′-tert-butyl-2′-hydroxy-5′-(2-isooctyloxycarbonylethyl)phenyl-benzotriazole,2,2′-methylene-bis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazol-2-yl-phenol];transesterification product of2-[3′-tert-butyl-5′-(2-methoxycarbonylethyl)-2′-hydroxy-phenyl]-benzotriazolewith polyethylene glycol 300; [R—CH₂CH₂—COO(CH₂)₃]₂— whereinR=3′-tert-butyl-4′-hydroxy-5′-2H-benzotriazol-2-yl-phenyl.

2. 2-Hydroxybenzophenones, such as the 4-hydroxy, 4-methoxy, 4-octyloxy,4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4,2′,4′-trihydroxy or2′-hydroxy-4,4′-dimethoxy derivative.

3. Esters of unsubstituted or substituted benzoic acids, such as4-tert-butyl-phenyl salicylate, phenyl salicylate, octylphenylsalicylate, dibenzoylresorcinol, bis(4-tert-butylbenzoyl)resorcinol,benzoylresorcinol, 3,5-di-tert-butyl-4-hydroxybenzoic acid2,4-di-tert-butylphenyl ester, 3,5-di-tert-butyl-4-hydroxybenzoic acidhexadecyl ester, 3,5-di-tert-butyl-4-hydroxybenzoic acid octadecylester, 3,5-di-tert-butyl-4-hydroxybenzoic acid2-methyl-4,6-di-tert-butylphenyl ester.

4. Acrylates, such as α-cyano-β,β-diphenylacrylic acid ethyl ester orisooctyl ester, α-carbomethoxy-cinnamic acid methyl ester,α-cyano-β-methyl-p-methoxy-cinnamic acid methyl ester or butyl ester,α-carbomethoxy-p-methoxy-cinnamic acid methyl ester,N-(β-carbomethoxy-β-cyanovinyl)-2-methyl-indoline.

5. Sterically hindered amines, such asbis(2,2,6,6-tetramethyl-piperidyl)sebacate,bis(2,2,6,6-tetramethyl-piperidyl)succinate,bis(1,2,2,6,6-pentamethylpiperidyl)sebacate,nbutyl-3,5-di-tert-butyl-4-hydroxybenzyl-malonic acidbis(1,2,2,6,6-pentamethylpiperidyl)ester, condensation product of1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinicacid, condensation product ofN,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and4-tert-octylamino-2,6-dichloro-1,3,5-s-triazine,tris(2,2,6,6-tetramethyl-4-piperidyl)nitrilotriacetate,tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetraoate,1,1′-(1,2-ethanediyl)-bis(3,3,5,5-tetramethyl-piperazinone),4-benzoyl-2,2,6,6-tetramethylpiperidine,4-stearyloxy-2,2,6,6-tetramethylpiperidine,bis(1,2,2,6,6-pentamethylpiperidyl)-2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate,3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione,bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)sebacate,bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)succinate, condensationproduct ofN,N′-bis(2,2,6,6-tetra-methyl-4-piperidyl)hexamethylenediamine and4-morpholino-2,6-dichloro-1,3,5-triazine, condensation product of2-chloro-4,6-di(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazineand 1,2-bis(3-amino-propylamino)ethane, condensation product of2-chloro-4,6-di(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazineand 1,2-bis(3-aminopropylamino)ethane,8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione,3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidine-2,5-dione,3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidyl)-pyrrolidine-2,5-dione.

6. Oxalic acid diamides, such as 4,4′-dioctyloxy-oxanilide,2,2′-diethoxy-oxanilide, 2,2′-di-octyloxy-5,5′-di-tert-butyl-oxanilide,2,2′-didodecyloxy-5,5′-di-tert-butyl-oxanilide,2-ethoxy-2′-ethyl-oxanilide, N,N′-bis(3-dimethylaminopropyl)oxalamide,2-ethoxy-5-tert-butyl-2′-ethyloxanilide and a mixture thereof with2-ethoxy-2′-ethyl-5,4′-di-tert-butyl-oxanilide, mixtures of o- andp-methoxy- and of o- and p-ethoxy-di-substituted oxanilides.

7. 2-(2-Hydroxyphenyl)-1,3,5-triazines, such as2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine,2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-(2,4-di-hydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2,4-bis(2-hydroxy-4-propyloxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine,2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazine,2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-[2-hydroxy-4-(2-hydroxy-3-butyloxy-propyloxy)phenyl]-4,6-bis(2,4-dimethyl-phenyl)-1,3,5-triazine,2-[2-hydroxy-4-(2-hydroxy-3-octyloxy-propyloxy)phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-[4-dodecyl-/tridecyl-oxy-(2-hydroxypropyl)oxy-2-hydroxy-phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine.

8. Phosphites and phosphonites, such as triphenyl phosphite, diphenylalkyl phosphites, phenyl dialkyl phosphites, tris(nonylphenyl)phosphite,trilauryl phosphite, trioctadecyl phosphite, distearyl-pentaerythritoldiphosphite, tris(2,4-di-tert-butylphenyl)phosphite,diisodecylpentaerythritol diphosphite,bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite,bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite,bis-isodecyloxy-pentaerythritol diphosphite,bis(2,4-di-tert-butyl-6-methylphenyl)pentaerythritol diphosphite,bis-(2,4,6-tri-tert-butylphenyl)pentaerythritol diphosphite,tristearyl-sorbitol triphosphite,tetrakis(2,4-di-tert-butylphenyl)-4,4′-biphenylene diphosphonite,6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenzo[d,g]-1,3,2-dioxaphosphocine,6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenzo[d,g]-1,3,2-dioxaphosphocine,bis(2,4-di-tert-butyl-6-methylphenyl)methyl phosphite,bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite.

Such light stabilisers can also be added, for example, to an adjacentsurface-coating layer from which they gradually diffuse into the layerof stoving lacquer to be protected. The adjacent surface-coating layermay be a primer under the stoving lacquer or a finishing lacquer overthe stoving lacquer.

It is also possible to add to the composition, for example,photosensitisers which shift or increase the spectral sensitivity sothat the irradiation period can be reduced and/or other light sourcescan be used. Examples of photosensitisers are aromatic ketones oraromatic aldehydes (as described, for example, in U.S. Pat. No.4,017,652), 3-acyl-coumarins (as described, for example, in U.S. Pat.No. 4,366,228, EP 738928, EP 22188), keto-coumarines (as described e.g.in U.S. Pat. No. 5,534,633, EP 538997, JP 8272095-A), styryl-coumarines(as described e.g. in EP 624580), 3-(aroylmethylene)-thiazolines,thioxanthones, condensed aromatic compounds, such as perylene, aromaticamines (as described, for example, in U.S. Pat. No. 4,069,954 or WO96/41237) or cationic and basic colourants (as described, for example,in U.S. Pat. No. 4,026,705), for example eosine, rhodanine anderythrosine colourants, as well as dyes and pigments as described forexample in JP 8320551-A, EP 747771, JP 7036179-A, EP 619520, JP6161109-A, JP 6043641, JP 6035198-A, WO 93/15440, EP 568993, JP5005005-A, JP 5027432-A, JP 5301910-A, JP 4014083-A, JP 4294148-A, EP359431, EP 103294, U.S. Pat. No. 4,282,309, EP 39025, EP 5274, EP727713, EP 726497 or DE 2027467.

Other customary additives are—depending on the intended use—opticalbrighteners, fillers, pigments, e.g. latent pigments, dyes, colourants,wetting agents or flow improvers.

For curing thick and pigmented coatings, the addition of micro glassbeads or powdered glass fibres, as described in U.S. Pat. No. 5,013,768,is suitable. Other examples of additional photoinitiators or additiveshave been given hereinbefore.

The choice of additive is made depending on the field of application andon properties required for this field. The additives described above arecustomary in the art and accordingly are added in amounts which areusual in the respective application.

Oximesulfonates can also be used, for example, in hybrid systems. Thesesystems are based on formulations that are full cured by two differentreaction mechanisms. Examples thereof are systems that comprisecomponents that are capable of undergoing an acid-catalysed crosslinkingreaction or polymerisation reaction, but that also comprise furthercomponents that crosslink by a second mechanism. Examples of the secondmechanism are radical full cure, oxidative crosslinking orhumidity-initiated crosslinking. The second curing mechanism may beinitiated purely thermally, if necessary with a suitable catalyst, oralso by means of light using a second photoinitiator.

If the composition comprises a radically crosslinkable component, thecuring process, especially of compositions that are pigmented (forexample with titanium dioxide), can also be assisted by the addition ofa component that is radical-forming under thermal conditions, such as anazo compound, for example2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile), a triazene, adiazosulfide, a pentazadiene or a peroxy compound, such as, for example,a hydroperoxide or peroxycarbonate, for example tert-butylhydroperoxide, as described, for example, in EP 245639. The addition ofredox initiators, such as cobalt salts, enables the curing to beassisted by oxidative crosslinking with oxygen from the air.

The surface coating can be applied by one of the methods customary inthe art, for example by spraying, painting on or immersion. Whensuitable surface coatings are used, electrical application, for exampleby electroimmersion coating, is also possible. After drying, the surfacecoating film is irradiated. If necessary, the surface coating film isthen fully cured by means of heat treatment.

The compounds of formulae I, II or III can also be used for curingmouldings made from composites. A composite consists of aself-supporting matrix material, for example a glass fibre fabric,impregnated with the photocuring formulation.

Resist systems can be prepared by image-wise irradiation of systemscomprising compounds of formulae I, II or III, followed by a developingstep. As already mentioned above, compounds of formulae I, II or III canbe used as photosensitive acid donors in a photoresist.

The invention accordingly relates also to a photoresist comprising asphotosensitive acid donor at least one oximesulfonate compound offormulae I, II or III.

The difference in solubility between irradiated and non-irradiatedsections that occurs as a result of the acid-catalysed reaction of theresist material during or after irradiation of the resist may be of twotypes depending upon which further constituents are present in theresist. If the compositions according to the invention comprisecomponents that increase the solubility of the composition in thedeveloper after irradiation, the resist is positive. If, on the otherhand, those components reduce the solubility of the composition afterirradiation, the resist is negative.

The invention accordingly relates also to a negative photoresist and toa positive photoresist.

The oximesulfonates of formulae I, II or III can also be used inchemically amplified resists. A chemically amplified photoresist isunderstood to be a resist composition the photosensitive component ofwhich, when irradiated, provides only that amount of acid that isrequired to catalyse a chemical reaction of at least one acid-sensitivecomponent of the resist, as a result of which the ultimate differencesin solubility between irradiated and non-irradiated areas of thephotoresist first develop.

The invention accordingly relates also to a chemically amplifiedphotoresist.

Subject of the invention further is the use of a compound of the formulaI or II as photosensitive acid donor in a photoresist.

Such resists exhibit an outstanding lithographic sensitivity toradiation of different wavelength, since compounds of formulae I, II orIII can be easily tuned over a broad range of the electromagneticspectrum. The photoresists according to the invention have excellentlithographic properties, especially a high sensitivity, and homogeneousexposure-conditions over the whole resist thickness due to the fact thatthe optical absorption is bleached upon irradiation.

Acid-sensitive components that produce a negative resist characteristicare especially compounds that, when catalysed by acid (the acid formedduring irradiation of the compounds of formulae I, II or III), arecapable of undergoing a crosslinking reaction with themselves and/orwith one or more further components of the composition. Compounds ofthat type are, for example, the known acid-curable resins, such as, forexample, acrylic, polyester, alkyd, melamine, urea, epoxy and phenolicresins or mixtures thereof. Amino resins, phenolic resins and epoxyresins are very suitable. Acid-curable resins of that type are generallyknown and are described, for example, in Ullmann's Encyclopädie dertechnischen Chemie, 4th Edition, Vol. 15 (1978), p. 613-628. Thecrosslinker components should generally be present in a concentration offrom 2 to 40, preferably from 5 to 30, percent by weight, based on thetotal solids content of the negative composition.

Especially preferred as acid-curable resins are amino resins, such asnon-etherified or etherified melamine, urea, guanidine or biuret resins,especially methylated melamine resins or butylated melamine resins,corresponding glycolurils and urones. There are to be understood byresins in this context both customary technical mixtures, whichgenerally also comprise oligomers, and pure and high purity compounds.N-Methoxymethyl melamine and tetramethoxymethyl glucoril andN,N′-dimethoxymethylurone are the acid-curable resins given the greatestpreference.

The concentration of the compound of formula I, II or III in negativeresists is in general from 0.1 to 30, preferably up to 20, percent byweight, likewise based on the total solids content of the compositions.From 1 to 15 percent by weight is especially preferred.

Where appropriate, the negative compositions may additionally comprise afilm-forming polymeric binder. That binder is preferably analkali-soluble phenolic resin. Well suited for that purpose are, forexample, novolaks, derived from an aldehyde, for example acetaldehyde orfurfuraldehyde, but especially from formaldehyde, and a phenol, forexample unsubstituted phenol, mono- or di-chlorosubstituted phenol, suchas p-chlorophenol, phenol mono- or di-substituted by C₁-C₉alkyl, such aso-, m- or p-cresol, the various xylenols, p-tert-butylphenol,p-nonylphenol, p-phenylphenol, resorcinol, bis(4-hydroxyphenyl)methaneor 2,2-bis(4-hydroxyphenyl)propane. Also suitable are homo- andco-polymers based on ethylenically unsaturated phenols, for examplehomopolymers of vinyl- and 1-propenyl-substituted phenols, such asp-vinylphenol or p-(1-propenyl)phenol or copolymers of these phenolswith one or more ethylenically unsaturated materials, for examplestyrenes. The amount of binder should generally be from 30 to 99 percentby weight, e.g. 30 to 95 percent by weight or 40 to 80 percent byweight, preferably, from 40 to 95 percent by weight.

The invention thus includes, as a special embodiment, as alreadymentioned above, negative, alkali-developable photoresists, comprisingan oximesulfonate of formula I, II or III as described above, analkali-soluble phenolic resin as binder and a component that whencatalysed by an acid undergoes a crosslinking reaction with itselfand/or with the binder. An especially preferred form of that negativeresist comprises from 1 to 15 percent by weight oximesulfonate, from 40to 95 percent by weight of a phenolic resin as binder, for example oneof those mentioned above, and from 0.5 to 30 percent by weight of amelamine resin as crosslinking agent, the percentages relating to thesolids content of the composition. With novolak or especially withpolyvinyl phenol as binder, a negative resist having especially goodproperties is obtained.

Oximesulfonates can also be used as acid generators, which can beactivated photochemically, for the acid-catalysed crosslinking of, forexample, poly(glycidyl)methacrylates in negative resist systems. Suchcrosslinking reactions are described, for example, by Chae et al. inPollimo 1993, 17(3), 292.

Monomeric or polymeric compounds that are alkali-insoluble but arecleaved in the presence of acid, or are capable of being rearrangedintramolecularly, in such a manner that reaction products remain thatare soluble in a customary alkaline developer and/or that cause anotherwise alkali-insoluble and acid-resistant additional binder tobecome soluble in the developer, produce a positive characteristic inphotoresist compositions according to the invention. Substances of thattype are referred to hereinafter as solution inhibitors.

As already indicated hereinbefore, the invention therefore includes, asa further special embodiment, positive alkaline-developablephotoresists, comprising a compound of formula I, II or III and at leastone compound that substantially prevents the composition from dissolvingin an alkaline developer, but that can be cleaved in the presence of anacid in such a manner that reaction products remain that are soluble inthe developer and/or that cause an acid-resistant additional binder thatwould otherwise be virtually insoluble in the developer to dissolve inthe developer.

There may be used as solution inhibitors monomeric and polymeric organiccompounds having functional groups that would be soluble per se in analkaline medium, for example aromatic hydroxy groups, carboxylic acidgroups, secondary amino groups and keto or aldehyde groups, but thathave been chemically so altered by reaction with a suitable compoundthat they are insoluble in aqueous alkali, the protecting groups formedin the mentioned reaction being capable of being cleaved again by acidcatalysis in such a manner that the functional groups are recovered intheir original form.

For the protection of hydroxy groups, carboxylic acid groups orsecondary amino groups there are suitable, for example, dihydrofuran or3,4-dihydropyran and the derivatives thereof, benzyl halides, alkylhalides, haloacetic acid, haloacetic acid esters, chlorocarbonic acidesters, alkylsulfonyl halides, aromatic sulfonyl halides, dialkyldicarbonates or trialkylsilyl halides, it being possible for thereactions to form the protected derivatives to be carried out in knownmanner. Customary conversion into ketals and acetals is suitable forprotecting keto and aldehyde groups.

Such chemically amplified positive resist systems are described, forexample, in E. Reichmanis, F. M. Houlihan, O. Nalamasu, T. X. Neenan,Chem. Mater. 1991, 3, 394; or in C. G. Willson, “Introduction toMicrolithography, 2nd. Ed.; L. S. Thompson, C. G. Willson, M. J. Bowden,Eds., Amer. Chem. Soc., Washington D.C., 1994, p. 139.

In positive resists of the mentioned type a film-forming, polymericsolution inhibitor can either be the only binder in the photoresist orcan be used in admixture with an acid-inert binder and, whereappropriate, a monomeric solution inhibitor.

Examples of acid-inert binders are novolaks, especially those based ono-, m- or p-cresol and formaldehyde, also poly(p-hydroxystyrene),poly(p-hydroxy-α-methylstyrene) and copolymers of p-hydroxystyrene,p-hydroxy-α-methylstyrene and acetoxystyrene.

Examples of polymeric solution inhibitors are novolaks, especially thosebased on o-, m- or p-cresol and formaldehyde, poly(p-hydroxystyrene),poly(p-hydroxy-α-methylstyrene), copolymers of p-hydroxystyrene orp-hydroxy-α-methylstyrene and acetoxystyrene or acrylic acid and/ormethacrylic acid and (meth)acrylic acid esters, which are reacted inknown manner with dihydrofuran, 3,4-dihydropyran, benzyl halides, alkylhalides, haloacetic acid, haloacetic acid esters, chlorocarbonic acidesters, alkylsulfonyl halides, aromatic sulfonyl halides, dialkyldicarbonate or trialkylsilyl halides. Also suitable are polymers ofp-(2-tetrahydropyranyl)-oxystyrene orp-(tert-butyloxycarbonyl)-oxystyrene with (meth)acrylic acid,(meth)acrylic acid esters and/or p-acetoxystyrene and polymers ofp-hydroxystyrene and/or p-(2-tetrahydropyranyl)-oxystyrene with3-hydroxybenzyl(meth)acrylates, which can, if necessary, additionally beprotected by reaction with one of the compounds listed above.

Especially suitable are polymers that are—depending on the light sourcesused for irradiation—transparent in the wavelength range used forirradiation. Wavelengths can vary between 180 and 1500 nm. The polymerscan carry both, groups that, after acid-catalysed deprotecting, bringabout a change in solubility, and hydrophobic and hydrophilic groupsthat increase the solubility of the acid generator and ensureaqueous-alkaline developability. Examples of such polymers are acrylatesand methacrylates prepared by co-, ter-, or quater-polymerisation fromthe corresponding monomers like methyl(meth)acrylate, (meth)acrylicacid, tert-butyl(meth)acrylate, 3-oxocyclohexyl(meth)acrylate,tetrahydropyranyl(meth)acrylate, adamantyl(meth)acrylate,cyclohexyl(meth)acrylate, norbornyl(meth)acrylate. The monomers can alsocombine two of above mentioned structures like for example(2-tetrahydropyranyl)oxynorbonylalcohol acrylates or(2-tetrahydropyranyl)oxymethyltricyclododecanemethanol methacrylates.Examples for such monomers are given in U.S. Pat. No. 5,621,019. Themonomers may also carry organosilicon radicals in order, for example, tofurther increase the resistance in the case of dry etching processes,like for example trimethylsilylmethyl(meth)acrylate.

The invention accordingly also relates to a chemically amplifiedpositive resist comprising as photosensitive acid donor a compound offormula I, II or III.

The invention relates also to a photoresist comprising polymers that aretransparent down to the wavelength region of 180 nm.

A special embodiment of the positive resist according to the inventioncomprises from 75 to 99.5 percent by weight of a film-forming polymerthat contains protecting groups (at the concentration from 1 to 60 molpercent, preferably from 5 to 50 mol percent against the amount ofhydroxyl groups in the polymer) that can be removed by acid catalysis,and from 0.5 to 25 percent by weight of oximesulfonates of formula I, IIor III, the percentages being based on the solids content of thecompositions. In this context, preference is given to compositionscomprising from 80 to 99 percent by weight of the mentioned polymer andfrom 1 to 20 percent by weight of oximesulfonate.

Another embodiment is a positive resist comprising from 40 to 90 percentby weight of an acid-inert film-forming polymer as binder, from 5 to 40percent by weight of a monomeric or polymeric compound having protectinggroups removable by acid catalysis and from 0.5 to 25 percent by weightof oximesulfonates of formula I, II or III, the percentages relating tothe solids content of the compositions. Of those compositions,preference is given to those comprising from 50 to 85 percent by weightacid-inert binder, from 10 to 30 percent by weight monomeric orpolymeric solution inhibitor and from 1 to 20 percent by weight, e.g.from 1 to 15 percent by weight, oximesulfonates.

Oximesulfonates can also be used as solubility enhancers, which can beactivated by light. In that case, the compounds are added to afilm-forming material comprising substantially no components thatpolymerise with the oximesulfonic acid ester when heated or whenirradiated with actinic radiation. However, the oximesulfonates reducethe speed at which the film forming material dissolves in a suitabledeveloper medium. That inhibiting effect can be cancelled by irradiatingthe mixture with actinic radiation, so that a positive image can beproduced. Such an application is described, for example, in EP 241423.

A further special embodiment of the invention is, finally, a positiveresist comprising a compound of formula I, II or III and a binder thatis virtually insoluble in an alkaline developer and that becomes solublein the developer in the presence of the photolysis products of thecompound of formula I, II or III. In this case the amount of thementioned oximesulfonate compound is generally from 5 to 50 percent byweight, based on the solids content of the composition.

The use of the oximesulfonates according to the invention in chemicallyamplified systems, which operates on the principle of the removal of aprotecting group from a polymer, generally produces a positive resist.Positive resists are preferred to negative resists in many applications,especially because of their greater resolution. There is, however, alsointerest in producing a negative image using the positive resistmechanism, in order to combine the advantages of the high degree ofresolution of the positive resist with the properties of the negativeresist. That can be achieved by introducing a so-called image-reversalstep as described, for example, in EP 361906. For that purpose, theimage-wise irradiated resist material is treated, before the developingstep, with, for example, a gaseous base, the acid that has been producedimage-wise being neutralised. Then, a second irradiation, over its wholearea, and thermal aftertreatment are carried out and the negative imageis then developed in the customary manner.

In addition to the mentioned constituents, both the negative and thepositive photoresist compositions may additionally comprise one or moreof the additives customarily used in photoresists in the amountsfamiliar to a person skilled in the art, for example flow improvers,wetting agents, adhesives, thixotropic agents, colourants, pigments,fillers, solubility accelerators and so on. The reaction can beaccelerated by the addition of photosensitisers which shift and/orbroaden the spectral sensitivity. These are especially aromatic carbonylcompounds, such as benzophenone, thioxanthone, anthraquinone and3-acylcoumarin derivatives and also 3-(aroylmethylene)thiazolines, butalso eosine, rhodanine and erythrosine colourants.

Other compounds that accelerate the acid formation or enhance the acidconcentration may also be used in combination with the oximesulfonatesof the formulae I; II or III according to the invention in positive ornegative resists or imaging systems as well as in all coatingapplications. Such acid amplifiers are described e.g. in Arimitsu, K. etal. J. Photopolym. Sci. Technol. 1995, 8, pp 43; Kudo, K. et al. J.Photopolym. Sci. Technol. 1995, 8, pp 45; Ichimura, K. et al. Chem:Letters 1995, pp 551.

For application, the compositions must generally also comprise asolvent. Examples of suitable solvents are ethyl acetate,3-methoxymethyl propionate, ethyl pyruvate, 2-heptanone, diethyl glycoldimethyl ether, cyclopentanone, cyclohexanone, γ-butyrolactone, ethylmethyl ketone, 2-ethoxyethanol, 2-ethoxyethyl acetate and especially1-methoxy-2-propyl acetate. The solvent may also be in the form amixture, for example of two or more of the abovementioned solvents. Thechoice of solvent and the concentration depend, for example, on thenature of the composition and on the coating method.

The solution is uniformly applied to a substrate by means of knowncoating methods, for example by spin-coating, immersion, knife coating,curtain pouring techniques, brush application, spraying and reverseroller coating. It is also possible to apply the photosensitive layer toa temporary, flexible support and then to coat the final substrate bycoating transfer (laminating).

The amount applied (coating thickness) and the nature of the substrate(coating substrate) are dependent on the desired field of application.The range of coating thicknesses can in principle include values fromapproximately 0.01 μm to more than 100 μm.

Possible areas of use of the composition according to the invention areas follows: use as photoresists for electronics, such as etchingresists, electroplating resists or solder resists, the manufacture ofintegrated circuits or thin film transistor-resist (TFT); themanufacture of printing plates, such as offset printing plates or screenprinting stencils, use in the etching of mouldings or instereolithography or holography techniques. The coating substrates andprocessing conditions vary accordingly.

The compositions according to the invention are also outstandinglysuitable as coating compositions for substrates of all types, includingwood, textiles, paper, ceramics, glass, plastics, such as polyesters,polyethylene terephthalate, polyolefins or cellulose acetate, especiallyin the form of films, but especially for coating metals, such as Ni, Fe,Zn, Mg, Co or especially Cu and Al, and also Si, silicon oxides ornitrides, to which an image is to be applied by means of image-wiseirradiation.

After the coating operation, the solvent is generally removed byheating, resulting in a layer of the photoresist on the substrate. Thedrying temperature must of course be lower than the temperature at whichcertain components of the resist might be thermally cured. Care must betaken in that respect especially in the case of negative photoresists.In general, drying temperatures should not exceed from 80 to 130° C.

The resist coating is then irradiated image-wise. The expression“image-wise irradiation” includes irradiation in a predetermined patternusing actinic radiation, i.e. both irradiation through a mask containinga predetermined pattern, for example a transparency, and irradiationusing a laser beam that is moved over the surface of the coatedsubstrate, for example under the control of a computer, and thusproduces an image. Another way to produce a pattern is by interferenceof two beams or images as used for example in holographic applications.It is also possible to use masks made of liquid crystals that can beaddressed pixel by pixel to generate digital images, as is, for exampledescribed by A. Bertsch; J. Y. Jezequel; J. C. Andre in Journal ofPhotochemistry and Photobiology A: Chemistry 1997, 107 p 275-281 and byK. P. Nicolay in Offset Printing 1997, 6, p 34-37.

After the irradiation and, if necessary, thermal treatment, theunirradiated sites (in the case of positive resists) or the irradiatedsites (in the case of negative resists) of the composition are removedin a manner known per se using a developer.

It is generally necessary to allow a certain period of time prior to thedeveloping step in order to allow the acid-sensitive components of theresist composition to react. In order to accelerate that reaction andhence the development of a sufficient difference in solubility betweenthe irradiated and unirradiated sections of the resist coating in thedeveloper, the coating is preferably heated before being developed. Theheating can also be carried out or begun during the irradiation.Temperatures of from 60 to 150° C. are preferably used. The period oftime depends on the heating method and, if necessary, the optimum periodcan be determined easily by a person skilled in the art by means of afew routine experiments. It is generally from a few seconds to severalminutes. For example, a period of from 10 to 300 seconds is verysuitable when a hotplate is used and from 1 to 30 minutes when aconvection oven is used. It is important for the latent acid donorsaccording to the invention in the unirradiated sites on the resist to bestable under those processing conditions.

The coating is then developed, the portions of the coating that, afterirradiation, are more soluble in the developer being removed. Ifnecessary, slight agitation of the workpiece, gentle brushing of thecoating in the developer bath or spray developing can accelerate thatprocess step. The aqueous-alkaline developers customary in resisttechnology may be used, for example, for the developing. Such developerscomprise, for example, sodium or potassium hydroxide, the correspondingcarbonates, hydrogen carbonates, silicates or metasilicates, butpreferably metal-free bases, such as ammonia or amines, for exampleethylamine, n-propylamine, diethylamine, di-n-propylamine,triethylamine, methyl diethylamine, alkanolamines, for example dimethylethanolamine, triethanolamine, quaternary ammonium hydroxides, forexample tetramethylammonium hydroxide or tetraethylammonium hydroxide.The developer solutions are generally up to 0.5N, but are usuallydiluted in suitable manner before use. For example solutions having anormality of approximately 0.1 are well suited. The choice of developerdepends on the nature of the photocurable surface coating, especially onthe nature of the binder used or of the resulting photolysis products.The aqueous developer solutions may, if necessary, also compriserelatively small amounts of wetting agents and/or organic solvents.Typical organic solvents that can be added to the developer fluids are,for example, cyclohexanone, 2-ethoxyethanol, toluene, acetone,isopropanol and also mixtures of two or more of those solvents. Atypical aqueous/organic developer system is based onButylcellosolve®/water.

It is known from EP 592139 that oximesulfonates can be used as acidgenerators, which can be activated by light in compositions that aresuitable for the surface treatment and cleaning of glass, aluminium andsteel surfaces. The use of those compounds in such organosilane systemsresults in compositions that have significantly better storage stabilitythan those obtained when the free acid is used.

Oximesulfonates can also be used to produce so-called print-out” imageswhen the compound is used together with a colourant that changes colourwhen the pH changes, as described e.g. in Japanese Patent Application JP4 328552-A or in U.S. Pat. No. 5,237,059. Such colourchange systems canbe used according to EP 199672 also to monitor goods that are sensitiveto heat or radiation. In addition the newly claimed compounds of formulaI, II or III exhibit already a colour change on their own when they areexposed to light of suitable wavelength. This color-change must not beas pronounced as in the case of using it in combination with thebeforementioned acid-sensitive colourants, but it is well visible.

In addition to a colour change, it is possible during the acid-catalyseddeprotection of soluble pigment molecules (as described e.g. in EP648770, EP 648817 and EP 742255) for the pigment crystals to beprecipitated; this can be used in the production of colour filters asdescribed e.g. in EP 654711 or print out images and indicatorapplications, when the colour of the latent pigment precursor differsfrom that of the precipitated pigment crystal.

Compositions using pH sensitive dyes or latent pigments in combinationwith oximesulfonates can be used as light indicators or simple throwaway dosimeters. Especially for light, that is invisible to the humaneye, like UV- or IR-light, such dosimeters are of interest.

The oximesulfonates of the present invention can also be used to shapepolymers that undergo an acid induced transition into a state where theyhave the required properties using photolithography. For instance theoximesulfonates can be used to pattern conjugated emissive polymers asdescribed in M. L. Renak; C. Bazan; D. Roitman; Advanced materials 1997,9, 392. Such patterend emissive polymers can be used to manufacturemicroscalar patterned Light Emitting Diodes (LED) which can be used tomanufacture displays and data storage media. In a similar way precursorsfor polyimides (e.g. polyimid precursors with acid labile protectinggroups that change solubility in the developer) can be irradiated toform patterned polyimide layers which can serve as protective coating,insulating layers and buffer layers in the production of microchips andprinted circuit boards.

The formulations may also be used as conformal coatings, photoimagabledielectricas as they are used in sequential build up systems for printedcricuit boards, stress buffer layers and isolation layers in themanufacturing of computer chips.

It is known that conjugated polymers like, e.g. polyanilines can beconverted from semiconductive to conductive state by means of protondoping. The oxime-sulfonates of the present invention can also be usedto imagewise irradiate compositions comprising such conjugated polymersin order to form conducting structures (exposed areas) embedded ininsulating material (non exposed areas). These materials can be used aswiring and connecting parts for the production of electric andelectronic devices.

Suitable for the crosslinking of compositions comprising compounds offormula I, II or III are radiation sources that emit radiation of awavelength of approximately from 150 to 1500, for example from 180 to1000 or preferably from 240 to 700 nanometers. Both point sources andplaniform projectors (lamp carpets) are suitable. Examples are: carbonarc lamps, xenon arc lamps, medium pressure, high pressure and lowpressure mercury lamps, optionally doped with metal halides (metalhalide lamps), microwave-excited metal vapour lamps, excimer lamps,superactinic fluorescent tubes, fluorescent lamps, argon filament lamps,electronic flash lamps, photographic flood lights, electron beams andX-ray beams generated by means of synchrotrons or laser plasma. Thedistance between the lamp and the substrate according to the inventionto be irradiated can vary, for example, from 2 cm to 150 cm, accordingto the intended use and the type and/or strength of the lamp. Suitablelight sources are therefore especially mercury vapour lamps, especiallymedium and high pressure mercury lamps, from the radiation of whichemission lines at other wavelengths can, if desired, be filtered out.That is especially the case for relatively short wavelength radiation.The distance between the lamp and the workpiece can vary, for example,from 2 cm to 150 cm, according to the intended use and the type and/orstrength of the lamp. It is, however, also possible to use low energylamps (for example fluorescent tubes) that are capable of emitting inthe appropriate wavelength range. An example thereof is the Philips TL03lamp. Another type of light source that can be used are the lightemitting diodes (LED) that emitt at different wavelength throughout thewhole spectrum either as small band emitting source or as broad band(white light) source. Also suitable are laser light sources, for exampleexcimer lasers, such as Kr—F lasers for irradiation at 248 nm or Ar—Flasers at 193 nm. Lasers in the visible range and in the infrared rangecan also be used. Very especially suitable is radiation of the mercury hand g lines at wavelengths of 436 and 405 nanometers. A suitablelaser-beam source is, for example, the argon-ion laser, which emitsradiation at wavelengths of 454, 458, 466, 472, 478, 488 and 514nanometers. Nd-YAG-lasers emitting light at 1064 nm and it's second andthird harmonic (532 nm and 355 nm respectively) can also be used. Alsosuitable is, for example, a helium/cadmium laser having an emission at442 nm or lasers that emit in the UV range. With that type ofirradiation, it is not absolutely essential to use a photomask incontact with the photopolymeric coating to produce a positive ornegative resist; the controlled laser beam is capable of writingdirectly onto the coating. For that purpose the high sensitivity of thematerials according to the invention is very advantageous, allowing highwriting speeds at relatively low intensities. On irradiation, theoximesulfonate in the composition in the irradiated sections of thesurface coating decomposes to form sulfonic acids.

In contrast to customary UV curing with high-intensity radiation, withthe compounds according to the invention activation is achieved underthe action of radiation of relatively low intensity. Such radiationincludes, for example, daylight (sunlight), and radiation sourcesequivalent to daylight. Sunlight differs in spectral composition andintensity from the light of the artificial radiation sources customarilyused in UV curing. The absorption characteristics of the compoundsaccording to the invention are as well suitable for exploiting sunlightas a natural source of radiation for curing. Daylight-equivalentartificial light sources that can be used to activate the compoundsaccording to the invention are to be understood as being projectors oflow intensity, such as certain fluorescent lamps, for example thePhilips TL05 special fluorescent lamp or the Philips TL09 specialfluorescent lamp. Lamps having a high daylight content and daylightitself are especially capable of curing the surface of a surface-coatinglayer satisfactorily in a tack-free manner. In that case expensivecuring apparatus is superfluous and the compositions can be usedespecially for exterior finishes. Curing with daylight ordaylight-equivalent light sources is an energy-saving method andprevents emissions of volatile organic components in exteriorapplications. In contrast to the conveyor belt method, which is suitablefor flat components, daylight curing can also be used for exteriorfinishes on static or fixed articles and structures.

The surface coating to be cured can be exposed directly to sunlight ordaylight-equivalent light sources. The curing can, however, also takeplace behind a transparent layer (e.g. a pane of glass or a sheet ofplastics).

The compounds of formulae I, II or III are generally added to thecompositions in an amount from 0.1 to 30% by weight, for example from0.5 to 10% by weight, especially from 1 to 5% by weight.

Subject of the invention is a method of crosslinking compounds that canbe crosslinked under the action of an acid, which method comprisesadding a compound of formula I, II and/or III to the above-mentionedcompounds and irradiating imagewise or over the whole area with lighthaving a wavelength of 180-1500 nm.

The invention relates also to the use of compounds of formulae I, II orIII as photosensitive acid donors in the preparation of surfacecoatings, printing inks, printing plates, dental compositions, colourfilters, resist materials or image-recording materials, orimage-recording materials for recording holographic images, as well asto a method for the preparation of surface coatings, printing inks,printing plates, dental compositions, colour filters, resist materialsand as image-recording material, or image-recording material forrecording holographic images, which comprises irradiating a compositionaccording to the invention with light having a wavelength of 180-1500nm.

The invention further pertains to the use of a composition as describedabove for the preparation of surface coatings, printing inks, printingplates, dental compositions, colour filters, resist materials and asimage-recording material, or image-recording material for recordingholographic images as well as to a method for the preparation of surfacecoatings, printing inks, printing plates, dental compositions, colourfilters, resist materials and as image-recording material, orimage-recording material for recording holographic images, whichcomprises irradiating a composition as described above with light havinga wavelength in the range of 180-1500 nm.

The examples which follow illustrate the invention in more detail. Partsand percentages, as in the remainder of the description and in theclaims, are by weight unless indicated otherwise.

EXAMPLE 1 2-Methylsulfonyloxyimino-4-phenyl-but-3-enenitrile

3.44 g (0.02 mol) of 2-hydroxyimino-4-phenyl-but-3-enenitrile, (mp127-129° C., prepared from cinnamaldoxime according to C. Trione et al,J. Org. Chem. 1993, 58, 2075) are dissolved in 20 ml of anhydroustetrahydrofuran and cooled to 0° C. Methanesulfonyl chloride (1.7 ml,0.022 mol) is added at once, followed by triethylamine (4.2 ml, 0.03mol) dropwise over 15 min, keeping the temperature of the mixture at 5°C. The mixture is then stirred at 25° C. for two hours, and poured into150 ml of iced water. The off-white precipitate is washed with ether,dried and recrystallyzed from 70 ml of ethanol, yielding 2.74 g (55%) of2-methylsulfonyloxyimino-4-phenyl-but-3-enenitrile as colorlesscrystals, mp. 144-148° C. No attempt is made to recover more materialfrom the ether extract.

Elemental analysis: C₁₁H₁₀N₂O₃S (250.28) C [%] H [%] N [%] calculated:52.79 4.03 11.19 found: 52.85 4.42 11.28

EXAMPLE 2 2-Methylsulfonyloxyimino-4-p-tolyl-but-3-enenitrile 2.1:4-p-tolyl-but-3-enenitrile

6.17 g (0.03 mol) of 4-methyl-benzenediazonium tetrafluoroborate (mp105-110° C.; prepared by nitrosation of p-toluidine with sodium nitritein aqueous fluoboric acid according to A. Roe, Org. Reactions vol V,1949,193) are suspended in 60 ml of ethanol. Allyl cyanide (4.0 g; 0.06mol) and palladium acetate (67 mg; 0.3 mmol) are added, and the lightorange suspension is heated gently to 46° C., at which temperature agentle evolution of nitrogen is visible. The mixture is stirred at thesame temperature until the nitrogen evolution ceases (ca 3 h), resultingin a dark brown clear solution. The reaction mixture is poured into 300ml of cold water and extracted with 2×100 ml of hexane:ethyl acetate85:15 (v:v). The organic phases are washed with saturated aqueous sodiumbicarbonate, water, brine, and dried over magnesium sulfate. The lightgreen solution is concentrated to ca 20 ml by rotary evaporation, andallowed to crystallize in the refrigerator. Filtration yields 2.5 g(53%) of 4-p-tolyl-but-3-enenitrile as very thin, colorless leaflets, mp60-61° C., consisting of the pure (E) isomer, as determined by ¹H-NMR.

2.2: 2-Hydroxyimino-4-p-tolyl-but-3-enenitrile

In a 3-necked 50 ml flask fitted with a sintered glass gas inlet tube,2.13 g (0.0135 mol) of 4-p-tolyl-but-3-enenitrile are dissolved in 30 mlof methanol, and cooled to 0° C. Sodium hydroxide (0.54 g; 0.0135 mol)is added. The turbid, slightly brownish mixture is then treated with ca.0.025 mol of gaseous methyl nitrite bubbled below the surface of themixture through the gas inlet tube (methyl nitrite is generated bydropwise addition of [0.8 ml of H₂SO₄ conc+1.6 ml H₂O] to a suspensionof sodium nitrite (1.72 g; 0.025 mol) in 3 ml of methanol:water 1:1(v:v); see M. Itoh et al. Org. Synth. Coll vol. VI, 1988, 199). Themixture is then stirred overnight, allowing the temperature to rise to25° C. The solvent is evaporated in vacuo, the residue is redissolved inwater and extracted with toluene. The aqueous phase is then acidifiedwith conc. HCl to pH ca 2, the beige precipitate is filtered, rinsedneutral with water, and dried under vacuum. The crude product isredissolved in ethyl acetate, filtered through a short pad of SiO₂, andevaporated. 2-Hydroxyimino-4-p-tolyl-but-3-enenitrile (1.9 g; 76%), mp135-137° C. is obtained and used without further purification.

2.3: 2-Methanesulfonyloxyimino-4-p-tolyl-but-3-enenitrile

2-Hydroxyimino-4-p-tolyl-but-3-enenitrile (1.9 g; 0.01 mol) is dissolvedin 15 ml of anhydrous tetrahydrofuran, and cooled to 0° C.Methanesulfonyl chloride (0.93 ml, 0.012 mol) is added at once, followedby triethylamine (2.1 ml, 0.015 mol) dropwise over 20 min, keeping thetemperature of the mixture below 5° C. The mixture is then stirred at5-10° C. for 3.5 hours, and poured into 200 ml of iced water. Thesuspension is extracted with ethyl acetate, the organic extract iswashed neutral with water, then with brine, and dried over magnesiumsulfate. Rotary evaporation of the solvent and recrystallization from 50ml of ethanol yields2-methanesulfonyloxyimino-4-p-tolyl-but-3-enenitrile (1.7 g; 64%) asoff-white crystals, mp 134-135° C. with one part melting at 145° C.¹H-NMR reveals the presence of two isomers (probably E/Z around theimino double bond).

Elemental analysis: C₁₂H₁₂N₂O₃S (264.30) C [%] H [%] N [%] calculated:54.53 4.58 10.60 found: 54.58 4.76 10.72

EXAMPLE 3 2-Methylsulfonyloxyimino-4-(4-methoxy-phenyl)-but-3-enenitrile3.1: Benzoic acid 1-cyano-3-(4-methoxy-phenyl)-allyl ester

Acetonitrile (25 ml) is added to a solution of potassium carbonate (3.45g; 0.025 mol) in 15 ml of water and the mixture is cooled to 0° C.4-Methoxycinnamaldehyde (8.1 g; 0.05 mol) dissolved in acetonitrile (25ml) is added dropwise under efficient stirring over 30 min, keeping thetemperature between 0 and 2° C., and the yellow mixture is furtherstirred 2 h at the same temperature. The phases are separated, theorganic layer is washed with brine, dried over magnesium sulfate, andevaporated. The crude benzoic acid 1-cyano-3-(4-methoxyphenyl)-allylester (15 g), obtained as a pale yellow oil, is used for the next stepwithout further purification.

3.2: 4-(4-Methoxy-phenyl)-but-3-enenitrile

Benzoic acid 1-cyano-3-(4-methoxy-phenyl)-allyl ester (15 g; ca 0.050mol) is dissolved in 100 ml of anhydrous tetrahydrofuran.Tetrakis(triphenylphosphine)palladium (0.88 g; 0.8 mmol) and 4.8 ml ofpoly(methylhydrosiloxane) (ca 80 meq; Aldrich) are added, and themixture is stirred at ca 20° C., cooling with a cold water bath. After 3h 30 min, the mixture is concentrated by rotary evaporation, stirredwith 150 ml of water to hydrolyze the siloxane. The polymer and organicmaterials are redissolved in CH₂Cl₂ and washed with saturated sodiumbicarbonate to remove benzoic acid. Evaporation of the solvent and flashchromatography (150 g SiO₂; hexane:ethyl acetate 80:20 v:v) affords 4.9g (57%) of pure 4-(4-methoxy-phenyl)-but-3-enenitrile, mp 75-76° C.

3.3: 2-Hydroxyimino-4-(4-methoxy-phenyl)-but-3-enenitrile

4-(4-Methoxy-phenyl)-but-3-enenitrile (5.0 g; 0.025 mmol) dissolved in90 ml of methanol is treated with ca 0.050 mol of gaseous methyl nitritein the same way as described in example 2.2. After stirring overnight atca 25° C., the reaction mixture is rotary evaporated and partitionedbetween 200 ml of 0.5 N HCl and 200 ml ethyl acetate. The aqueous phaseis extracted with 50 ml of ethyl acetate. The combined organic extractsare evaporated and purified by flash chromatography (150 g SiO₂;hexane:ethyl acetate 80:20 v:v); to yield2-hydroxyimino-4-(4-methoxy-phenyl)-but-3-enenitrile 1.8 g (36%) as ayellow solid which is used for the next reaction without furtherpurification.

3.4: 2-Methylsulfonyloxyimino-4-(4-methoxy-phenyl)-but-3-enenitrile

2-hydroxyimino-4-(4-methoxy-phenyl)-but-3-enenitrile (1.8 g; 9 mmol) isdissolved in 15 ml of anhydrous tetrahydrofuran, and cooled to 0° C.Methanesulfonyl chloride (0.93 ml, 0.012 mol) is added at once, followedby triethylamine (2 ml, 0.015 mol) dropwise over 20 min, keeping thetemperature of the mixture below 5° C. The mixture is then stirred at 2°C. for 1 h 15 min, and poured into 200 ml of iced water. The suspensionis extracted with ethyl acetate, the organic extract is washed neutralwith water, then with brine, and dried over magnesium sulfate. Rotaryevaporation of the solvent and recrystallization from 80 ml of ethanolyields 2-methylsulfonyloxyimino-4-(4-methoxy-phenyl)-but-3-enenitrile(1.02 g; 41%) as light yellow hair-like crystals, mp 147-152° C. (dec).¹H-NMR reveals the presence of only one isomer.

Elemental analysis: C₁₂H₁₂N₂O₄S (280.30) C [%] H [%] N [%] calculated:51.42 4.32 9.99 found: 51.81 4.51 9.90

EXAMPLE 4 2-Methylsulfonyloxyimino-3-methyl-4-phenyl-but-3-enenitrile

1.5 g (ca 8 mmol) of crude2-hydroxyimino-3-methyl-4-phenyl-but-3-enenitrile (prepared according toC. Trione et al, J. Org. Chem. 1993, 58, 2075 fromα-methylcinnamaldoxime and obtained as a brown oil) is treated withmethanesulfonyl chloride and triethylamine as described in example 3.4.The crude product is a brown oil which crystallizes upon triturationwith hexane:ethyl acetate 80:20 (v:v). Recrystallization from 20 mlethanol affords2-methylsulfonyloxyimino-3-methyl-4-phenyl-but-3-enenitrile (0.86 g;41%) as light beige crystals, mp 105-107° C.

Elemental analysis: C₁₂H₁₂N₂O₃S (264.30) C [%] H [%] N [%] calculated:54.53 4.58 10.60 found: 54.74 4.76 10.52

EXAMPLE 5 2-Methylsulfonyloxyimino-3-oxo-5-phenyl-pent-4-enenitrile 5.1:2-Hydroxyimino-3-oxo-5-phenyl-pent-4-enenitrile

Cinnamoyl acetonitrile (5.1 g; 0.03 mol) is dissolved in 50 ml of aceticacid. 10 ml of H₂O are added and the mixture is cooled to 3° C. in anice/salt bath. Partial precipitation occurs, but the mixture remainswell stirrable. Sodium nitrite (4.14 g; 0.06 mol) is added by portionsover 10 min, keeping the temperature between 3 and 5° C. Completesolution is observed during addition, but precipitation occurs againtowards the end. The mixture is then stirred at 0° C. for 1.5 h. Themixture is diluted with 100 ml of iced water with stirring, the lightochre precipitate is filtered, and washed with ca 100 ml of water. Thehumid cake is redissolved in ether (100 ml), washed with water, brineand dried over magnesium sulfate. Rotary evaporation and drying affords2-hydroxyimino-3-oxo-5-phenyl-pent-4-enenitrile (4.7 g; 78%) as a darkyellow solid (mp 144-145° C. dec) which is used without furtherpurification in the next reaction step.

5.2: 2-Methylsulfonyloxyimino-3-oxo-5-phenyl-pent-4-enenitrile

2-Hydroxyimino-3-oxo-5-phenyl-pent-4-enenitrile (4.0 g; 0.02 mol) istreated with methanesulfonyl chloride and triethylamine as described inexample 3.4. The crude brown product is recrystallized from 40 ml ofethanol. 2-Methylsulfonyloxyimino-3-oxo-5-phenyl-pent-4-enenitrile (2.2g; %) is obtained as a light ochre solid (mp 163-165° C.).

EXAMPLE 64-{4-[4-(3-Cyano-3-methanesulfonyloxyimino-propenyl)-benzyl]-phenyl}-2-methanesulfonyloxyimino-but-3-enenitrile

in formula II,

R₂=CN, R₃=—SO₂CH₃, R₄=R₅=H, m=0, n=1

6.1: 4,4′-Methanediyl-bis-benzenediazonium tetrafluoroborate

4,4′-Diaminodiphenylmethane (19.83 g; 0.10 mol) is dissolved in anaqueous solution of fluorboric acid (0.6 mol in 200 ml) at 0° C. Sodiumnitrite (13.8 g; 0.20 mol) dissolved in 30 ml of water is then addeddropwise at 4° C. during 1 h. A cream-colored precipitate is formedduring the addition. After stirring for additional 1.5 h, the fineprecipitate is filtered, washed with ice-cold 5% aqueous HBF₄ (40 ml),cold methanol (35 ml), and ether (120 ml). The crude product is dried inair overnight at room temperature, yielding 27.8 g (70%) of4,4′-methanediyl-bis-benzenediazonium tetrafluoroborate as a tan solid,melting point 96-99° C. (dec).

6.2: 4-{4-[4-(3-Cyano-propenyl)-benzyl]-phenyl}-but-3-enenitrile

A suspension of 4,4′-methanediyl-bis-benzenediazonium tetrafluoroborate(11.9 g, 0.03 mol), prepared according to the method of example 6.1,allyl cyanide (8.05 g; 0.12 mol), and palladium acetate (0.135 g, 0.6mmol) in 80 ml of ethanol is heated at 40° C. during 22 h. Theheterogeneous reaction mixture is poured into 300 ml of water, extractedwith ethyl acetate, washed with water, brine, dried over MgSO₄, andevaporated. The crude beige product is recrystallized from 130 ml ofethanol, yielding 5.44 g (61%) of4-{4-[4-(3-cyano-propenyl)-benzyl]-phenyl}-but-3-enenitrile as lightbeige crystals, melting point 128-130° C.

6.3:4-{4-[4-(3-Cyano-3-hydroxyimino-propenyl)-benzyl]-phenyl}-2-hydroxyimino-but-3-enenitrile

A solution of sodium hydroxide (0.8 g; 0.02 mol) in 30 ml of methanol isadded to a suspension of4-{4-[4-(3-cyano-propenyl)-benzyl]-phenyl}-but-3-enenitrile (3.0 g; 0.01mol), prepared as described in example 6.2, in 20 ml of methanol. Methylnitrite, generated from 2.07 g (0.03 mol) of sodium nitrite as describedin example 2.2, is bubbled through the suspension at 2° C. for 25 min,and the mixture is then left at room temperature for 48 h. The solventis then evaporated, the residue is dissolved in 200 ml of water,extracted with toluene (the extract is discarded), and acidified withconc. hydrochloric acid. The beige precipitate is taken up in ethylacetate, washed neutral with water, dried (MgSO₄) and concentrated byevaporation. 2.7 g (76%) of4-{4-[4-(3-cyano-3-hydroxyimino-propenyl)-benzyl]-phenyl}-2-hydroxyimino-but-3-enenitrileare obtained as a light brown solid, melting point 142-145° C. (dec).

6.4:4-{4-[4-(3-Cyano-3-methanesulfonyloxyimino-propenyl)-benzyl]-phenyl}-2-methanesulfonyloxyimino-but-3-enenitrile

4-{4-[4-(3-Cyano-3-methanesulfonyloxyimino-propenyl)-benzyl]-phenyl}-2-methanesulfonyloxyimino-but-3-enenitrile(2.7 g; 7.6 mmol), prepared as described in example 6.3, is dissolved in15 ml of anhydrous tetrahydrofuran, and cooled to 0° C. Methanesulfonylchloride (1.30 ml; 16.8 mmol) is added at once, followed by dropwiseaddition of triethylamine (3.2 ml; 23 mmol) during 35 min, keeping thetemperature between 2° C. and 6° C. The mixture is then stirred at roomtemperature for 5 h, poured into 300 ml of iced water, extracted withdichloromethane, washed with aq. sat. NaHCO₃, water, brine, and driedover MgSO₄. Rotary evaporation and recrystallization from toluene (40ml) affords 0.65 g (17%) of4-{4-[4-(3-cyano-3-methanesulfonyloxyimino-propenyl)-benzyl]-phenyl}-2-methanesultonyloxyimino-but-3-enenitrile,as a light brown solid, melting point 178-186° C. (dec). ¹H NMR (CDCl₃),δ [ppm]: 7.5 (6H, m), 7.2 (4H, m), 6.96 (2H, d, J=16.2 Hz), 4.06 (2H, m,(Ar)₂CH₂), 3.27 (6H, m, CH₃S).

EXAMPLE 72-[4′-(1-Cyano-3-p-tolyl-allylideneaminooxysulfonyl)-biphenyl-4-ylsulfonyloxyimino]-4-p-tolyl-but-3-enenitrile

in formula III, R₁=4-tolyl, R₂=CN,

R₄=R₅=H, m=0, n=1

5.0 g (0.027 mol) of 2-hydroxyimino-4-p-tolyl-but-3-enenitrile (preparedas described in example 2.2) are dissolved in 15 ml of anhydroustetrahydrofuran. Triethylamine (3.1 g; 0.03 mol) is added, and thesolution is cooled to 5° C. Diphenyl-4,4′-disulfonyl chloride (4.29 g;0.012 mol) dissolved in 35 ml of anhydrous THF is added dropwise over 90min, keeping the temperature between 5 and 10° C. A thick, beigesuspension forms, and 25 ml of THF are added to keep the mixture wellstirrable. After 22 h at room temperature, the mixture is poured intowater, the beige solid is filtered and washed neutral with water anddried i.v. at 40° C. The crude product is taken up in ethanol, filteredand dried i.v. at 40° C. The desired product,2-[4′-(1-cyano-3-p-tolyl-allylideneaminooxysulfonyl)-biphenyl-4-ylsulfonyloxyimino]-4-p-tolyl-but-3-enenitrile,7.7 g (90%) is obtained as a light beige solid, melting point >200° C.

Elemental analysis: C₃₄H₂₆N₄O₆S₂ (650.74) C [%] H [%] N [%] S [% ]calculated: 62.76 4.03 8.61 9.85 found: 62.90 4.02 8.53 9.90

EXAMPLE 7 Preparation of a Negative Resist

A resist solution is prepared by dissolving 65 parts of polyvinylphenol(Mw=4.000, Maruzen Chemicals Co. Ltd.), 30 parts ofhexa(methoxymethyl)melamine (^(RTM)CYMEL 303, Cyanamid) and 5 parts ofthe latent acid to be tested in 7.5 g of 1-methoxy-2-propylacetate,which contains 1000 ppm of an anti-foaming agent (FC430). This solutionis spin coated onto the polished side of a silicon wafer (diameter 4inch), which has been pretreated with hexamethyldisilazane, by spinningat 6100 rpm for 30 seconds. The solvent is removed by drying the coatedwafer for 60 seconds at 110° C. on a hot plate (pre-bake). Resulting arefilms of 1 μm thickness. Irradiation of the samples is performed with aCanon maskaligner (Canon PLA 501) using interference filters to selectthe wavelengths at 365, 405 and 436 nm. For each wavelength a fixed doseis used, but due to the lower output of the lamp and absorption of thelatent acid, longer irradiation times respectively higher doses are usedat longer wavelength in order to cause sufficient crosslinking. Aspecial mask containing a greyscale step wedge (transmissions rangingfrom 0 to 50%) and resolution patterns is used. After exposure thewafers are heated for 60 seconds to 110° C. to perform the post exposurebake (PEB) during which the liberated acid catalyses the crosslinkingreaction in the irradiated areas. Developing is performed by dipping thesamples into a 2.38% solution of tetramethyl ammonium hydroxide (TMAH)for 60 seconds. The thickness of the film before exposure as well asafter exposure in the fields that were exposed to different doses ismeasured with an Axiotron from Zeiss which uses white lightinterference. The thickness measurements are used to estimate theone-to-one energy E1:1 which is the dose that is required to retain thesame film thickness as before developing. The film thickness of thecured samples is also measured by means of an Alpha Step profilometer.The step with the highest number that is cured is used to calculate theminimum dose E0 required to achieve crosslinking. The smaller therequired dose the more reactive is the latent acid.

The results are listed in Table 1 and show that the latent acids havehigh sensitivity in a negative resist at all wavelengths.

TABLE 1 Latent acid Reactivity at Reactivity at Reactivity at compoundof 365 nm 405 nm 436 nm example (mJ/cm²) (mJ/cm²) (mJ/cm²) 1 E0 5 — —E1:1 7 2 E0 1.3 E0 135 — E1:1 1.7 E1:1 140 3 E0 0.7 E0 2.3 E0 37 E1:11.6 E1:1 5.5 E1:1 49 4 E0 7.2 — — E1:1 9.5

What is claimed is:
 1. Compounds of formulae I, II or III

m is zero or 1; n is 1, 2 or 3; R₁ is phenyl, which is unsubstituted orsubstituted by one or more of the radicals C₁-C₁₂alkyl, C₁-C₄haloalkyl,halogen, phenyl, OR₆, NR₇R₈, SR₉ and/or —S-phenyl, it being possible forthe substituents OR₆, SR₉ and NR₇R₈ to form 5- or 6-membered rings, viathe radicals R₆, R₇, R₈ and/or R₉, with further substituents on thephenyl ring or with one of the carbon atoms of the phenyl ring; or R₁ isnaphthyl, anthracyl or phenanthryl, wherein the radicals naphthyl,anthracyl and phenanthryl are unsubstituted or substituted byC₁-C₆alkyl, phenyl, OR₆, NR₇R₈, SR₉ and/or —S-phenyl, it being possiblefor the substituents OR₆, SR₉ and NR₇R₈ to form 5- or 6-membered rings,via the radicals R₆, R₇, R₈ and/or R₉ with further substituents on thenaphthyl, anthracyl or phenanthryl ring or with one of the carbon atomsof the naphthyl, anthracyl or phenanthryl ring; or R₁ is a heteroarylradical which is unsubstituted or substituted by C₁-C₆alkyl, phenyl,OR₆, NR₇R₈, SR₉ and/or —S-phenyl, it being possible for the substituentsOR₆, SR₉ and NR₇R₈ to form 5- or 6-membered rings, via the radicals R₆,R₇, R₈ and/or R₉ with further substituents on the heteroaryl ring orwith one of the carbon atoms of the heteroaryl ring; or R₁ isC₂-C₁₂alkenyl, C₄-C₈cycloalkenyl, or C₆-C₁₂bicycloalkenyl, with theproviso that the double bond (or the double bonds) of the radicalsC₂-C₁₂alkenyl, C₄-C₈cycloalkenyl, or C₆-C₁₂bicycloalkenyl is (are)conjugated with the double bond substituted by R₄ and R₅; or, if m iszero, R₁ additionally is benzoyl, 2-furoyl, 2-thio-phenecarbonyl,2-pyridinecarbonyl or 2-pyrrolecarbonyl, wherein the radicals benzoyl,2-furoyl, 2-thiophenecarbonyl, 2-pyridinecarbonyl or 2-pyrrolecarbonylare unsubstituted or substituted by one or more of the radicalsC₁-C₁₂alkyl, C₁-C₄haloalkyl, halogen, phenyl, OR₆, NR₇R₈, SR₉ and/or—S-phenyl, it being possible for the substituents OR₆, SR₉ and NR₇R₈ toform 5- or 6-membered rings, via the radicals R₆, R₇, R₈ and/or R₉, withfurther substituents on the benzoyl, 2-furoyl, 2-thiophenecarbonyl,2-pyridinecarbonyl or 2-pyrrolecarbonyl ring or with one of the carbonatoms of the benzoyl, 2-furoyl, 2-thiophenecarbonyl, 2-pyridinecarbonylor 2-pyrrolecarbonyl ring; or, if m is zero, n is 1 and simultaneouslyR₅ is phenyl which is unsubstituted or substituted by one or moreC₁-C₁₂alkyl, C₁-C₄haloalkyl, halogen, phenyl, OR₆, NR₇R₈, SR₉ and/or—S-phenyl, R₁ additionally is hydrogen or halogen; R′₁ is vinylene,phenylene, naphthylene,

 diphenylene or oxydiphenylene, wherein the radicals phenylene,naphthylene,

 diphenylene and oxydiphenylene are unsubstituted or substituted byC₁-C₁₂alkyl; R₂ is CN, C₁-C₄haloalkyl, C₂-C₆alkoxycarbonyl,phenoxycarbonyl, C₁-C₆alkyl-S(O)_(x)—, C₆-C₁₂aryl-S(O)x—, which isunsubstituted or substituted by C₁-C₁₂alkyl, or R₂ is C₁-C₆alkyl-SO₂O—,C₆-C₁₀aryl-SO₂O—, diphenyl-phosphinoyl or R₂ is benzoyl which isunsubstituted or substituted by CN, NO₂ or C₁-C₄haloalkyl; x is 1 or 2;R₃ is C₁-C₁₈alkylsulfonyl, phenyl-C₁-C₃alkylsulfonyl, camphorylsulfonyl,C₁-C₁₀haloalkylsulfonyl, phenylsulfonyl, naphthylsulfonyl,anthracylsulfonyl or phenanthrylsulfonyl, wherein the groups phenyl,naphthyl, anthracyl and phenanthryl of the radicalsphenyl-C₁-C₃alkylsulfonyl, phenylsulfonyl, naphthylsulfonyl,anthracylsulfonyl and phenanthrylsulfonyl are unsubstituted orsubstituted by one or more halogen, C₁-C₄haloalkyl, CN, NO₂,C₁-C₁₆alkyl, phenyl, C₁-C₄alkylthio, OR₆, COOR₉, C₁-C₄alkyl-OCO—,R₉OSO₂— and/or —NR₇R₈; or R₃ is C₂-C₆haloalkanoyl, halobenzoyl,triphenylsilyl, or a group

 or

Y₁, Y₂ and Y₃ are independently of each other O or S; R′₃ isC₂-C₁₂alkylenedisulfonyl, phenylenedisulfonyl, naphthylenedisulfonyl,

 diphenylenedisulfonyl, or oxydiphenylenedisulfonyl, wherein the groupsphenylene, naphthylene,

 diphenylene and oxydiphenylene of the radicals phenylenedisulfonyl,naphthylenedisulfonyl,

 diphenylenedisulfonyl, or oxydiphenylenedisulfonyl are unsubstituted orsubstituted by C₁-C₁₂alkyl; R₄ and R₅ are independently of each otherhydrogen, halogen, C₁-C₈alkyl, C₁-C₆alkoxy, C₁-C₄haloalkyl, CN, NO₂,C₂-C₆alkanoyl, benzoyl, phenyl, —S-phenyl, OR₆, SR₉, NR₇R₈,C₂-C₆alkoxycarbonyl or phenoxycarbonyl, or R₄ and R₅ together are adirect bond; R₆ is hydrogen, phenyl, C₁-C₁₂alkyl which is unsubstitutedor substituted by phenyl, OH, C₁-C₁₂alkoxy, C₁-C₁₂alkylsulfonyl,phenylsulfonyl, (4-methylphenyl)sulfonyl and/or by C₂-C₆alkanoyl, or R₆is C₂-C₁₂alkyl which is interrupted by one or more —O— or —S—, whereinthe interrupted C₂-C₁₂alkyl is unsubtstituted or substituted by phenyl,OH, C₁-C₁₂alkoxy, C₁-C₁₂alkylsulfonyl, phenylsulfonyl,(4-methylphenyl)sulfonyl and/or by C₂-C₆alkanoyl; R₇ and R₈ areindependently of each other hydrogen or C₁-C₁₂alkyl which isunsubstituted or substituted by OH, C₁-C₄alkoxy, C₁-C₁₂alkylsulfonyl,phenylsulfonyl, (4-methyl-phenyl)sulfonyl and/or C₁-C₆alkanoyl; or R₇and R₈ are C₂-C₁₂alkyl which is interrupted by one or more —O—, whereinthe —O-interrupted C₂-C₁₂alkyl is unsubtstituted or substituted by OH,C₁-C₄alkoxy, C₁-C₁₂alkylsulfonyl, phenylsulfonyl,(4-methylphenyl)sulfonyl and/or C₁-C₆alkanoyl; or R₇ and R₈ are phenyl,C₂-C₆alkanoyl, benzoyl, C₁-C₆alkylsulfonyl, phenylsulfonyl,(4-methylphenyl)sulfonyl, naphthylsulfonyl, anthracylsulfonyl orphenanthrylsulfonyl; or R₇ and R₈, together with the nitrogen atom towhich they are bonded, form a 5-, 6- or 7-membered ring which may beinterrupted by —O— or by —NR₆—; R₉ is C₁-C₁₂ alkyl which isunsubstituted or substituted by OH and/or C₁-C₄alkoxy, or R₉ isC₂-C₁₂alkyl which is interrupted by one or more —O— or —S— and whichinterrupted C₂-C₁₂alkyl is unsubstituted or substituted by OH and/orC₁-C₄alkoxy; R₁₀, R₁₁ and R₁₂ independently of one another areC₁-C₆alkyl which is unsubstituted or substituted by halogen; or R₁₀, R₁₁and R₁₂ are phenyl which is unsubstituted or substituted by C₁-C₄alkylor halogen; or R₁₁ and R₁₂ together are 1,2-phenylene or C₂-C₆alkylenewhich is unsubstituted or substituted by C₁-C₄alkyl or halogen; with theproviso that if m and n both are 1, R₄ and R₅ both are hydrogen and R₁is phenyl, R₃ is not p-tolylsulfonyl.
 2. Compounds of formula I,according to claim 1, wherein n is 1, m is zero or 1, R₁ isunsubstituted phenyl or phenyl substituted by C₁-C₄alkyl or OR_(6;) R₂is CN; R₃ is C₁-C₄alkylsulfonyl; and R₄ and R₅ independently of eachother are hydrogen or C₁-C₄alkyl.
 3. Compounds according to claim 1having the structure Ia,

wherein R₁, R₂, R₃, R₄ and R₅ are as defined in claim
 1. 4. Compounds offormula Ia, according to claim 3, wherein R₁ is unsubstituted phenyl orphenyl substituted once or twice by C₁-C₄alkyl, OR₆ or halogen or R₁ iscyclohexenyl, furyl or thienyl; R₂ is CN or trifluoromethyl; R₃ isC₁-C₁₆alkylsulfonyl; camphorylsulfonyl; or phenylsulfonyl which isunsubstituted or substituted 1-5 times by C₁-C₁₂alkyl, C₁-C₄alkoxy,C₁-C₄haloalkyl, C₁-C₄alkylthio, NO₂ or halogen; or R₃ is—P(O)(OR₁₁)(OR₁₂); R₄ and R₅ independently of each other are hydrogen,C₁-C₄alkyl, phenyl, C₁-C₄alkoxy or C₂-C₆₋alkoxycarbonyl; R₆ isC₁-C₄alkyl or C₁-C₄alkylsulfonyl; and R₁₁, R₁₂ are C₁-C₆alkyl or phenyl.5. A composition comprising a) at least one compound which can becrosslinked under the action of an acid and/or b) at least one compoundthe solubility of which is altered under the action of an acid and c) aslatent acid photoinitiator, at least one compound of formulae I, II orIII according to claim
 1. 6. A composition according to claim 5, whichcomprises in addition to component c) further photoinitiators,sensitisers and/or additives.
 7. A method for the preparation of surfacecoatings, printing inks, printing plates, dental compositions, colourfilters, resist materials and as image-recording material, orimage-recording material for recording holographic images, whichcomprises irradiating a composition according to claim 6 with lighthaving a wavelength in the range of 180-1500 nm.
 8. A method for thepreparation of surface coatings, printing inks, printing pates, dentalcompositions, colour filters, resist materials and as image-recordingmaterial, or image-recording material or recording holographic images,which comprises irradiating a composition according to claim 5 withlight having a wavelength in the range of 180-1500 nm.
 9. A method ofcrosslinking compounds which can be crosslinked under the action of anacid, which method comprises adding a compound of formula I, II and/orIII according to claim 1 to the above-mentioned compounds andirradiating imagewise or over the whole area with light having awavelength in the range of 180-1500 nm.
 10. A photoresist comprising asphotosensitive acid donor at least one compound of formula I, II and/orIII according to claim
 1. 11. A photoresist according to claim 10, whichphotoresist is a negative resist.
 12. A photoresist according to claim10, which photoresist is a positive resist.
 13. A photoresist accordingto claim 10, which photoresist is a chemically amplified resist.
 14. Aphotoresist according to claim 10, comprising polymers that aretransparent down to the wavelength region of 180 nm.
 15. Compounds offormula I or II according to claim 1, wherein m is zero or 1; n is 1; R₁is unsubstituted phenyl or phenyl which is substituted by C₁-C₆alkyl,phenyl, OR₆, SR₉, —S-phenyl, halogen and/or by NR₇R₆, it being possiblefor the substituents OR₆, and NR₇R₈ to form 5- or 6-membered rings, viathe radicals R₆, R₇ and/or R₈ with further substituents of the phenylring, or with one of the carbon atoms of the phenyl ring; or R₁ isC₄-C₈cycloalkenyl or C₆-C₁₂bicycloalkenyl; R′₁ is phenylene,naphthylene,

 diphenylene or oxydiphenylene, wherein the radicals phenylene,naphthylene,

 diphenylene and oxydiphenylene are unsubstituted or substituted byC₁-C₁₂alkyl.